 Carbs backfiring and hesitation
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Joined: Jul 2012
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QUESTION:
What are the different reasons that a carburetor would be back firing. I do not mean the popping on decel. I can hear the carbs popping through the air filters and there is hesitation. fuel mixture might not be right. It is very difficult to start with or without the choke. I have to open the throttle to get it to start. and it won't idle very well.
Carb popping causes:
1. vacuum leak
2. carbs need to be synched
3. carbs need to be cleaned (AGAIN)
4. fuel mixture is not right
These carbs were recently rebuilt at a local shop, and sadly, I don't trust the work from most any shop.
I have not rebuilt Triumph carbs, but I have rebuilt Honda Goldwing carbs, and Honda 750 carbs. So, I don't think I would have a problem doing this if necessary. But where is the best place to get a carb kit and a how to?
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Re: Carbs backfiring and hesitation
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Joined: Feb 2008
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Loquacious
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Loquacious
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Carb farts are generally a sign of overly lean mixture, either caused by a vacuum leak or improper tuning.
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Re: Carbs backfiring and hesitation
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Joined: May 2007
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Worn Saddle
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Worn Saddle
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I'd replace the four 'squirrel condoms' first.
A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. Herm Albright (1876 - 1944)
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Re: Carbs backfiring and hesitation
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oldroadie,
that was the very first thing I did.
And with having to open the throttle to start, combined with carb farts?
lean mixture?
I think we are getting somewhere.
Last edited by goregalore; 07/31/2012 7:43 AM.
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Re: Carbs backfiring and hesitation
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3/4 Throttle
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3/4 Throttle
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I all ways have to start the bike with the choke out and the bike backfired through the carbs during warm up....I just changed out the pilot jet to a 42 and put in Truxton needles...I don't need the choke to start,,didn't notice any carb backfire
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Re: Carbs backfiring and hesitation
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Joined: May 2007
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Worn Saddle
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Worn Saddle
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Quote:
oldroadie,
that was the very first thing I did.
And with having to open the throttle to start, combined with carb farts?
lean mixture?
I think we are getting somewhere.
Good about the vacuum caps. Since the carb is a CV and doesn't have an accelerator pump opening the throttle really doesn't do anything to start the motor. Have you opened the mix screws yet? Either that or one pilot size bigger is what I'm thinking. Go for the screws first, simple and cheap is always better.
A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. Herm Albright (1876 - 1944)
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Re: Carbs backfiring and hesitation
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I have NOT made any adjustments on the carbs yet. I am reading my owners manual etc... I honestly do not know much about this bike.
Like standard settings etc.
I want to know the basics before I start screwing with it, so I can atleast get it back to where it was before I started tinkering.
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Re: Carbs backfiring and hesitation
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3/4 Throttle
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3/4 Throttle
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I think what would help is what mod's have been made to the bike...so for example I have a 2006 speedmaster with British Custom cams, no air box K&N pods only and British Custom Cocktail Shaker pipes and I live at sea level.......all of this effects the jetting of the bike.
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Re: Carbs backfiring and hesitation
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Joined: Jul 2011
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Oil Expert
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Quote:
I think what would help is what mod's have been made to the bike...so for example I have a 2006 speedmaster with British Custom cams, no air box K&N pods only and British Custom Cocktail Shaker pipes and I live at sea level.......all of this effects the jetting of the bike.
exactly.
2007 Speedmaster and miss it!
2013 T-Bird Storm and Luvin it!
Catching a yellow jacket in your shirt at 70 mph can double your vocabulary
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Re: Carbs backfiring and hesitation
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Loquacious
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Loquacious
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When you said they were rebuilt, could you tell us what the dealer installed in terms of main and pilot jets along with the type of needles and if they were shimmed. You may have to pull off the float bowls to see what is in your carbs.
Because the bike won't start even with the choke pulled I'd say something is messed up or you have a big vacuum leak as already been stated. The choke is really an enricher that allows extra fuel to be drawn into the engine through another series of feed holes. You shouldn't have to open the throttle (unless you are really really rich?).
The next thing is to know what modifications have been done to the exhaust and intake. That will dictate what you should have in place.
I would agree with Ed and richen the two idle/pilot mixture screws, one under each carb. You might want to pull the plugs to see if you really are too lean. White = lean, Black = rich.
12 Rocket Roadster
03 Bonneville America
69 BSA Firebird Scrambler
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Re: Carbs backfiring and hesitation
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There were 2 mods.
1. removal of airbox and replacement with K&H pods
2. Sceptre exhaust from team triumph.
So those 2 combined will probably need new primary, and main jets
I am trying to find out from the previous owner if he replaced the jets when he had the carbs rebuilt.
Last edited by goregalore; 08/01/2012 6:38 PM.
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Re: Carbs backfiring and hesitation
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3/4 Throttle
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3/4 Throttle
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I am running 42 pilot, 145 main and truxton needles...like I said after I increased the pilot seemed to take out the carb backfire and need to use the choke on start up.
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Re: Carbs backfiring and hesitation
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Worn Saddle
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Worn Saddle
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Ah, modified at both ends. That's a horse of a different color; you'll need to open a carb up see what's in there before you can proceed. The main jet and pilot (slow) jet will need to be larger than stock with that much air flow.
A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. Herm Albright (1876 - 1944)
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Re: Carbs backfiring and hesitation
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Those mods are almost 10 years old. He said he changed out the jets, and will try to figure out what he changed them too.
The other symptom, I was riding and backed off just a little on the throttle and it sputtered and wanted to die.
But on my way home I got it to 90 without any issue at all. I could have easily gotten more out of it. But I had the wrong helmet and glasses on to handle that speed.
And I will pull the plugs to see if they are lean or rich.
Last edited by goregalore; 07/31/2012 7:42 PM.
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Re: Carbs backfiring and hesitation
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Fe Butt
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Fe Butt
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Carb to intake rubbers on the right way? (It does matter) Sticky valve after sitting? ( you did say it sat a while) Quote:
But on my way home I got it to 90 without any issue at all. I could have easily gotten more out of it. But I had the wrong helmet and glasses on to handle that speed.
I run an indicated 120mph on my way to work with no helmet and little round (John Lennon type) sunglasses.NOTGATT 
I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!
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 Re: Carbs backfiring and hesitation
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I will check. Sorry, Big Dog, I am not as much of a man as you are 
Last edited by goregalore; 07/31/2012 9:00 PM.
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Re: Carbs backfiring and hesitation
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Should be Riding
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Should be Riding
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Back in 2003 I recall when Robert had to reverse the direction of the manifold to carburetor rubbers. This was taken just after that exercise.  Click in this image for the post. 
Blowing gravel off rural roads
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Re: Carbs backfiring and hesitation
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Re: Carbs backfiring and hesitation
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New Tires
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New jets came with the Septres, so I would guess if someone was paying close to $600 for mufflers they would have changed to the Team Triumph recommended jets. What does your bike idle at and what are your AF screws turned out to?
Also, I may be wrong, but I thought opening the throttle was not advised when starting.
Once you've got this sorted out, balance the carbs, you'll be pleasantly shocked.
Every normal man must be tempted, at times, to spit on his hands, hoist the black flag, and begin slitting throats.
H. L. Mencken
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Re: Carbs backfiring and hesitation
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Thanks Macmc,
I called the septre rep and he knows Robert. the previous owner.
He said the jets they send are 45 pilot and 122 main.
But robert also installed the K&N filters.
I have a tach on the bike but it is not hooked up yet. So, I don't know what it is idling at, yet...
But I am sure now that the best thing I can do is just pull the carbs and clean them again. check the jets. and adjust the pilot screws.
Now where is the best place to get a new carb kit or atleast the gaskets.
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Re: Carbs backfiring and hesitation
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Fe Butt
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Fe Butt
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Not sure what altitude you live at but I bet you should have about a 150 to 155 main unless you have baffles in those Sceptres.
I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!
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Re: Carbs backfiring and hesitation
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Should be Riding
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Should be Riding
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Quote:
Thanks Macmc,
I called the septre rep and he knows Robert. the previous owner.
He said the jets they send are 45 pilot and 122 main.
But robert also installed the K&N filters.
I have a tach on the bike but it is not hooked up yet. So, I don't know what it is idling at, yet...
But I am sure now that the best thing I can do is just pull the carbs and clean them again. check the jets. and adjust the pilot screws.
Now where is the best place to get a new carb kit or at least the gaskets.
You are NOT running 45/122s with the freak. No way. And you have at least one shim under each main jet needle. You shouldn't need a gasket kit or anything else for the cleaning. Without reviewing your post, have you run through several tanks of fuel mixed with seafoam? When you clean the carbys, pay attention when you drop the jets and air mixture screws as the part order is crucial and the itty bitty o-rings and washers are hard on the eyes. Hum, never mind as you have been there before. 
Blowing gravel off rural roads
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Re: Carbs backfiring and hesitation
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From the research I have done and using the calculator. It should be 155 main and a 42 pilot with the pods and the exhaust, plus a shim.
But that sounds like a good plan. Run a couple tanks of seafoam might really help. The backfiring isn't that bad after it warms up.
Oh, and no bluing on the exhaust yet.
Oh man, please ALL the help I can get is great.
Last edited by goregalore; 08/02/2012 12:56 PM.
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Re: Carbs backfiring and hesitation
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3/4 Throttle
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3/4 Throttle
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Your carb should be easy to pull, with pods only...take the tank off, and un-screw the carb...they should slide out on the kick stand side..there is a allen head screw on the side of the carb bowl to drain the fuel...un-due the screw on the bottom of the bowl...main jet has a nut and screw on it the pilot is in a "hole" and you need a skinny screw driver to get it out...the jet size is marked on the side of the jet...should take a'bout 1 hour to do it....
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Re: Carbs backfiring and hesitation
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New Tires
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New Tires
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Quote:
Not sure what altitude you live at but I bet you should have about a 150 to 155 main unless you have baffles in those Sceptres.
I'm not sure the original Septres have baffles, mine don't.
Every normal man must be tempted, at times, to spit on his hands, hoist the black flag, and begin slitting throats.
H. L. Mencken
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Re: Carbs backfiring and hesitation
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Here is a shot of one of the plugs. Bike does appear to be running lean. -I did put seafoam in the tank. -I also adjusted the pilot screws. Right now at 3.75 turns out. Plan on riding to dinner tonight so should be able to run some fuel through the carbs. I live in Southern Indiana. SO elevation is not really an issue. Also checked the exhaust. No baffles. 
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Re: Carbs backfiring and hesitation
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Fe Butt
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Fe Butt
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If that is the correct pilot setting you probably need a larger pilot jet.
I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!
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Re: Carbs backfiring and hesitation
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Fe Butt
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Fe Butt
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I just know they made baffles for the Sceptres, I haven't seen anyone running them yet but know some do.42 pilot jet is gonna be too small with open pipes and pods.
I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!
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Re: Carbs backfiring and hesitation
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New Tires
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New Tires
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Dogg the original Septres didn't have baffles available, but I think they became available in later years. Isn't there a jet calculator somewhere, to help him? 
Every normal man must be tempted, at times, to spit on his hands, hoist the black flag, and begin slitting throats.
H. L. Mencken
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Re: Carbs backfiring and hesitation
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Seriously thank you gentleman,
Took an hour ride last night.
And it ran good but periodically had a carb pop. accel or decel, it didn't matter.
Then we got caught in a storm, riding a motorcycle with seeing that much lightening flashing across the sky right in front of you is awe inspiring. Luckily it wasn't raining that hard. But boy it hurt at times. I still loved it!
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Re: Carbs backfiring and hesitation
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Okay,
pulled the carbs.
155 main 42 pilot, and no shims.
Needle designation NBAD
And again we know the bike is running lean since the the plugs are white.
SO, I will closely check the carb to manifold rubbers to make sure they are good. And if so then I should order shims and a 45 pilot.
Last edited by goregalore; 08/03/2012 5:59 PM.
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Re: Carbs backfiring and hesitation
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I think we found the problem. This one is worse than the other. but both were cracked. Shall we say "VACUUM LEAK" 
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Re: Carbs backfiring and hesitation
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Worn Saddle
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Worn Saddle
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Ooh, that'll take the starch out of the throttle.
A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. Herm Albright (1876 - 1944)
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Re: Carbs backfiring and hesitation
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Ordered the head to carb rubbers from madss.com. 9.99 each RUBBER,HT, CARB TO HEAD ENG NO 55616 AND HIGHER US CAL ONLY bike bandit part #1388148 #8 on diagram carb schematic And ordered a 45 pilot and shims from fast eddys
Last edited by goregalore; 08/04/2012 7:14 PM.
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Re: Carbs backfiring and hesitation
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Saddle Sore
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Saddle Sore
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I would throw on those rubbers and run it for a while to see how she does before doing any additional mods.
We have to assume the carb set up is what Robert was running and I don't recall him having issues.
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Re: Carbs backfiring and hesitation
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Fe Butt
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Fe Butt
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Always best to make 1 change at a time to determine weather it is good or bad. If you make more than 1 change at a time you won't know what was good and what was bad if you have an adverse result.
I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!
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Re: Carbs backfiring and hesitation
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One thing at a time is the way to go. If I were you I would replace the rubber and see how it runs. Next I'd readjust the A/F screw and test that out. If all is well I'd sync the carbs before changing the jetting.
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Re: Carbs backfiring and hesitation
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That is what I was thinking I should do. I was just getting prepared.
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Re: Carbs backfiring and hesitation
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Should be Riding
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Should be Riding
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Quote:
I would throw on those rubbers and run it for a while to see how she does before doing any additional mods.
We have to assume the carb set up is what Robert was running and I don't recall him having issues.
+1.
Blowing gravel off rural roads
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Re: Carbs backfiring and hesitation
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Should be Riding
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Should be Riding
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Kevin, doesn't that take the cake? Really. "Please de-varnish my carburetors mr stealership" Okay oldcustomerwhomweusedtolovenowwewillripyouoff. Big4Cycle, Way to go. Brilliant attention to detail. Marvelous work. Exceptional diligence. R U KIDDING? Pull the carbs and not see the rubbers as bad? 
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Re: Carbs backfiring and hesitation
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Uh yeah,
Old owner bought the triumph here NEW.
These have had cracks in them for years... Both of them. Why would they not change them? Answer: Not in stock.
I called to buy what I thought would be a stock part on Sat thinking I could just leisurely run in and pick them up.
How could that NOT be a stock part I scoffed. And of course I was told they would have to be ordered.
SO, I said if I wanted to order them, "I could do that from 20 different websites". I could tell the parts guy was annoyed by that. I said if you had the part stocked I would pick them up right now. But no such luck.
wouldn't you think that would be a stock part?
Regardless, the parts are ordered. The carbs are back together and waiting for the rubbers.
Last edited by goregalore; 08/05/2012 9:19 AM.
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Re: Carbs backfiring and hesitation
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Should be Riding
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Should be Riding
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How long did they tell you you'll have to wait? I've got two sets of rubbers, one of which I could send you. (I replaced the original rubbers with oem ones before the original ones went bad.) Hum, you might want to order some aftermarket clamps for those rubbers. The oem clamps fail to tighten up sufficiently over time.
Blowing gravel off rural roads
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Re: Carbs backfiring and hesitation
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We didn't really get to that. I ordered them from www.madss.comThey said 5 to 6 days. I know these clamps are stainless and they are more narrow than standard worm clamps so I bet you they are the marine ones. Thank you Moe, that is VERY generous of you. I think I will be ok unless they ordered the wrong parts;)
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Re: Carbs backfiring and hesitation
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I just purchased both a oil temp gauge and an oil pressure gauge.
But I can't seem to find what the running oil temp and the running oil pressure should be.
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Re: Carbs backfiring and hesitation
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Fe Butt
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Fe Butt
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about 20 to 40 psi at idle depending on temp and about 80psi running and my bike runs around 190ºF more or l;ess depending on ambient temp. I made our oil pressure gauges for about $50 each if I remember right.   
I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!
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Re: Carbs backfiring and hesitation
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Super sweet!
thanks for such a fast response.
I have oil pressure on all my vehicles.
It helps prevent major damage.
This is my first oil temp and I bet it is an even faster indicator that something is about to go wrong, which should help prevent a real problem.
Every bike should have both on them.
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Re: Carbs backfiring and hesitation
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Learned Hand
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Learned Hand
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Quote:
Quote:
Not sure what altitude you live at but I bet you should have about a 150 to 155 main unless you have baffles in those Sceptres.
I'm not sure the original Septres have baffles, mine don't.
Mine did.
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Re: Carbs backfiring and hesitation
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Parts arrived today.
So, carb rubbers have been installed. With wide portion of divider facing up and with the rubber tab facing the heads.
The bike started right up with the choke and not using the throttle at all. After it warmed up with would idle just fine.
But as soon as I tried to use the throttle it would just die.
I tried adjusting the pilot screws up in both directions and it made no difference except the exhaust started getting a whump whump sound to it.
Not sure if I should try what Robert had to do which was reverse the carb rubbers.
I don't quite understand why that worked for him.
I thought the next step was to again check the plugs to see if they went from lean to rich and if so put the 45 pilot jet in.
I am again open to input here.
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Re: Carbs backfiring and hesitation
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Loquacious
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Are you sure that the carb boots are properly seated to the head & the carbs are properly seated in the boots? The tabs are supposed to face the head for a reason, I would not reverse them.
Did you check the vacuum piston rubbers (a/k/a slide diaphrams) for tears/cracks, & make sure they are seated properly?
42 pilots are on the small side for a bike with your mods and NBAD needles; I suggest that you make sure the slide rubbers are properly seated in the groove, & if so, then try two .5mm shims (1mm total) under each needle head & see if the situation improves.
Also, with the bike upright, run some clear plastic tubing from the carb bowl drain vertically up the side of the carb body, open the bowl drain screw a bit, & see where the fuel level is in the tube (with the fuel valve on or reserve, of course), relative to the bowl gasket...where exactly is each one?
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Re: Carbs backfiring and hesitation
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Joined: Jul 2012
Posts: 103
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Posts: 103 |
The nice thing is the heads have stops on them so you know when the rubbers are seated properly, And I just made sure the carbs were in the rubbers as far as I could get them until they almost hit the vacuum plugs.
Now, I know there are 4 vacuum rubbers on the carbs. ALL of them have been replaced. I will try to locate more rubbers and see if they are ok.
I will try to work with the bike this weekend.
And I do have shims to try.
I also know a 42 pilot was a little small.
But the shims is an easy trouble shoot to try first.
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Re: Carbs backfiring and hesitation
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Joined: May 2007
Posts: 6,432 Likes: 1
Worn Saddle
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Worn Saddle
Joined: May 2007
Posts: 6,432 Likes: 1 |
If you pull the tops plan some time to let the diaphragms dry, they'll have absorbed some fuel and expanded where they won't fit back in the groove. About an hour should be fine.
A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. Herm Albright (1876 - 1944)
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Re: Carbs backfiring and hesitation
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Joined: Jul 2011
Posts: 2,212
Oil Expert
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Oil Expert
Joined: Jul 2011
Posts: 2,212 |
well that made little sense, ran with the ripped boots, poorley at times but ran, now with the new ones runs worse? something wrong with the install of those boots.
Make sure you did not put a hole in your pods when you were re-installing everything.
Last edited by edmspeedmaster; 08/15/2012 10:47 AM.
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Re: Carbs backfiring and hesitation
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Joined: Apr 2007
Posts: 3,059 Likes: 8
Loquacious
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Loquacious
Joined: Apr 2007
Posts: 3,059 Likes: 8 |
Quote:
I tried adjusting the pilot screws up in both directions and it made no difference except the exhaust started getting a whump whump sound to it.
Adjusting the pilot screws up leans the mixture. Is that what you were trying to achieve? Even at 3.75 turns the bike should run and idle (maybe a little rough). The bike should have ran fine with the new boots set up the way it is.
Quote:
I thought the next step was to again check the plugs to see if they went from lean to rich and if so put the 45 pilot jet in.
I am again open to input here.
If the plugs went from lean to rich....going from 42 to 45 pilots will richen things up again???
Something happened when you opened up your carbs. Now you have to find it. I wouldn't change anything in terms of needles, shims or pilots because the bike ran well before the boots were cracked. As stated, check the float heights (might have been messed up when carbs opened), needles back in place properly, diaphragm rubbers in place properly and not pinched, and anything else that might have been touched when the carbs were opened.
12 Rocket Roadster
03 Bonneville America
69 BSA Firebird Scrambler
73 Yamaha TX 750
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Re: Carbs backfiring and hesitation
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Joined: Jan 2005
Posts: 6,308 Likes: 4
Worn Saddle
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Worn Saddle
Joined: Jan 2005
Posts: 6,308 Likes: 4 |
Quote:
Kevin, doesn't that take the cake? Really. "Please de-varnish my carburetors mr stealership" Okay oldcustomerwhomweusedtolovenowwewillripyouoff. Big4Cycle, Way to go. Brilliant attention to detail. Marvelous work. Exceptional diligence.
R U KIDDING? Pull the carbs and not see the rubbers as bad?
grrr ?
A word to the wise is not necessary. It is the stupid ones who need the advice.
Pat
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Re: Carbs backfiring and hesitation
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Joined: Jul 2012
Posts: 103
Adjunct
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OP
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Joined: Jul 2012
Posts: 103 |
Well,
I know the rubbers are on correctly.
Moe reminded me to check the vent on the tank. I might have pinched it.
The bike went from lean to rich.
That is expected.
On the pilots, I adjusted it down first to see if I could lean them out and then back up to 3 turns out since it didn't seem to make any difference.
I still have a feeling that the carbs aren't quite clean. I bet there is a passage blocked. But I will reserve that judgement until I can't get this troubleshooting to work.
This bike ran previously with the way it is set up before it sat for a couple years and then the carbs got lacquered up. So I know it should not need shims, or jet changes.
But I am going to try both electrical connection checks and the potential vacuum issues first.
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Re: Carbs backfiring and hesitation
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Joined: Jul 2012
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I checked the tank vent. No on that I looked over the electrical and checked the coils. They don't seem to be getting the best contact. It started raining so I didn't get to clean and tighten the battery terminals. I also opened up the carb tops, and the rubber is seated properly. I pulled the plugs and verified that it is running rich now from changing out the carb rubbers. That is the ONLY change I made to the bike. http://sphotos-b.xx.fbcdn.net/hphotos-ash4/253875_3760661415023_1793590280_n.jpg
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Re: Carbs backfiring and hesitation
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Joined: Feb 2007
Posts: 23,179 Likes: 55
Fe Butt
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Fe Butt
Joined: Feb 2007
Posts: 23,179 Likes: 55 |
when checking the tank vent did you also check the tip over valve?
I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!
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Re: Carbs backfiring and hesitation
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Joined: Jul 2012
Posts: 103
Adjunct
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OP
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Joined: Jul 2012
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Totally had a "DUH" light bulb moment tonight.
I know what is wrong.
I can't believe I did it.
I assembled the top end of the carbs in the wrong order.
I put the needle guide in and then dropped the needle in.
SO, I will fix it in about 10 minutes tonight.
And here I am saying how much simpler the triumph carbs are than Honda carbs and look what I do.
Jeeeze!
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Re: Carbs backfiring and hesitation
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Joined: Feb 2008
Posts: 2,671 Likes: 15
Loquacious
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Loquacious
Joined: Feb 2008
Posts: 2,671 Likes: 15 |
Guess you don't need the shims yet... 
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Re: Carbs backfiring and hesitation
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Joined: Jul 2012
Posts: 103
Adjunct
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Nope,
No need for shims;)
After figuring out what I did, I had it running in no more than 10 minutes. The af was set at 3 turns out and I could smell it was running a little rich, so adjusted back to 2.5 turns out. Less rich, and then took it for a 10 mile ride.
Need to check the spark plugs to see if they are in the normal range or still running rich.
Is so then need to change out the 42 for a 45 pilot to remedy the rich mix.
But hoping I don't need to do that. But I have a NEW sound to the exhaust with the lowered af mixture setting.
But it runs great. No flat spots.
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Brake rotor issues
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Joined: Jul 2012
Posts: 103
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Joined: Jul 2012
Posts: 103 |
Something that is looking to be an issue.
The back brake rotor doesn't look so good. It is grooved, a little rusty from sitting. And what is getting my attention is delaminating in a few spots. And a bit noisy on braking.
Can I sand the rotor or do I just need to change it out.
I need new tires so it would be great to do this at the same time if needed.
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Re: Carbs backfiring and hesitation
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Joined: Jul 2012
Posts: 103
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This speedmaster on ebay says it has Dunlop 404 whitewalls. But no front fender. This is the look I am going for. Are the 404s a good fit? http://cgi.ebay.com/ebaymotors/Triumph-B...2#ht_954wt_1165
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Re: Carbs backfiring and hesitation
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Joined: Apr 2007
Posts: 3,059 Likes: 8
Loquacious
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Loquacious
Joined: Apr 2007
Posts: 3,059 Likes: 8 |
Quote:
Need to check the spark plugs to see if they are in the normal range or still running rich.
Is so then need to change out the 42 for a 45 pilot to remedy the rich mix.
Once again, going from 42 to 45 pilots won't lean things out but richen it. Larger pilot jet numbers means richer settings. Going to a 45 pilot will richen things more.
12 Rocket Roadster
03 Bonneville America
69 BSA Firebird Scrambler
73 Yamaha TX 750
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Re: Carbs backfiring and hesitation
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Joined: Feb 2008
Posts: 2,671 Likes: 15
Loquacious
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Loquacious
Joined: Feb 2008
Posts: 2,671 Likes: 15 |
If it is running OK with the 42's, unless you have access to an air fuel meter then IMO leave it alone.
That said, you might want to lean-out the pilot screws by an eight to a quarter of a turn (turn them clockwise "in" to make leaner) at a time & retest each time; provided you don't get lean-surging at cruise or hesitation on acceleration, then fuel economy should improve. If you keep going until you encounter either lean-surging or hesitation, then you'll know where the lean limit is.
Keep in mind that the fuel mixture will automatically lean out in colder weather, all other things equal.
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Re: Brake rotor issues
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Joined: Feb 2008
Posts: 2,671 Likes: 15
Loquacious
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Loquacious
Joined: Feb 2008
Posts: 2,671 Likes: 15 |
Quote:
Something that is looking to be an issue.
The back brake rotor doesn't look so good. It is grooved, a little rusty from sitting. And what is getting my attention is delaminating in a few spots. And a bit noisy on braking.
Can I sand the rotor or do I just need to change it out.
I need new tires so it would be great to do this at the same time if needed.
I suggest measuring the rotor width to dertermine if it is still within spec; what is the remaining brake pad thickness? Without knowing that, it's hard to say.
You can clean up the "rust" with some steel wool & brake cleaner.
Given that this started as a carb thread & has now morphed into brakes you might want to start another thread focused on brakes.
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Re: Carbs backfiring and hesitation
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Joined: Aug 2007
Posts: 10,714 Likes: 4
Should be Riding
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Should be Riding
Joined: Aug 2007
Posts: 10,714 Likes: 4 |
Quote:
This speedmaster on ebay says it has Dunlop 404 whitewalls. But no front fender. This is the look I am going for. Are the 404s a good fit?
http://cgi.ebay.com/ebaymotors/Triumph-B...2#ht_954wt_1165
except for the pipes (and the sticker on the custom battery cover?) that looks just like Mikey790's bike...
Always remember to be yourself. Unless you suck. Then pretend to be someone else.
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Re: Carbs backfiring and hesitation
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Joined: Jul 2012
Posts: 103
Adjunct
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OP
Adjunct
Joined: Jul 2012
Posts: 103 |
Brakes,
there is next to NO pad on the back brakes.
Front looks ok.
On the carbs.
I leaned them out some but then when it came to starting.
I am having difficulty again.
When the needles were being held by the guides it started like a champ.
Now, lots of trouble.
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Re: Carbs backfiring and hesitation
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Joined: Feb 2008
Posts: 2,671 Likes: 15
Loquacious
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Loquacious
Joined: Feb 2008
Posts: 2,671 Likes: 15 |
Quote:
Brakes,
there is next to NO pad on the back brakes.
Front looks ok.
On the carbs.
I leaned them out some but then when it came to starting.
I am having difficulty again.
When the needles were being held by the guides it started like a champ.
Now, lots of trouble.
Carbs: gotta give us more detail to go on...your bike is now hard-starting with the enrichener (a/k/a "choke") full on (pulled out all the way)?
Brakes: replace the rear pads!
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Re: Carbs backfiring and hesitation
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Joined: Jul 2012
Posts: 103
Adjunct
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OP
Adjunct
Joined: Jul 2012
Posts: 103 |
choke full on no start
half choke no start
no choke no start
It took a good 5 minutes to get the bike started this morning after correcting the carbs yesterday.
I ordered white wall tires this morning and brake pads for front and back organic ebc pads through motorcycle superstore. I only bring it up because they do not list the part #, but you select the bike model.
And sent cad specs to my laser cutter for fender brackets to add the wider and taller front tires
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Re: Carbs backfiring and hesitation
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Joined: Feb 2008
Posts: 2,671 Likes: 15
Loquacious
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Loquacious
Joined: Feb 2008
Posts: 2,671 Likes: 15 |
Prsuming there is nothing else funky with the carbs (such as failed enrichener, which is possible) then perhaps your "new" issue is electrical...
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Re: Carbs backfiring and hesitation
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Joined: Jul 2012
Posts: 103
Adjunct
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OP
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Joined: Jul 2012
Posts: 103 |
I am planning on taking a harder look at that option. I tried to tighten up the coil connections, but still feel they could be tighter. And still planning on pulling the battery cable and checking those connections, cleaning etc...
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