Bonneville America Forums Forums Technical Forums Performance Mods Got a problem with my bike - help please

Just bought an 03 america used off another guy with 2300 miles on it...runs great, starts right up, no backfiring, or popping....at slower speeds.

My problem is when i get it up around 70 or 80 or into the higher rpms....i lose power, it breaks up, boggs down, stutters a alot....etc.

The guy I bought it off of was into all the standard customizations...so thats why im a bit puzzled.

He put a streetboogie intake system on it...with the k&n filters on a horsehoe piece that faces the filter foward

He put Dunstal 19" cocktail shakers on it with 1 of 2 baffles removed

So Im asking myself "did he re-jet it"?....

I found a bag with a bunch of different jets that he had kept in the air box....so its leads me to believe that he might of re-jeted it....especially because he seemed like the type of guy that did everything by the book when it comes to customization and working on triumphs in particular...(he had two customized 03's thats why he sold me this one)

I tried emailing him about this, but i got no response

My thought is that its getting too much air on the higher speeds and that i should take the air filters off the horseshoe piece and attach them directly to the carb...

My theory is that this keeps the cones out of the direct path of air when the bikes moving.

Any thoughts at all?

One more question while im posting..haha

i think he took the Air intake tubes off the bike...are the 2 bolts next to the spark plugs, the plug bolts for that modification? Are they supposed to be hollow on the inside of them? or a solid bolt?...these are hollow...does that make a difference in the way the bike runs?

thanks alot....great site

Tom

he must have cut the air injection tubes off and plugged them Oldroadie had the same set up when he bought his. The right block off for the air injection should be solid plugs.

Sounds like it's running out of fuel. With mileage that low I would doubt a clogged fuel filter but not out of the question. Play with jetting and carb adjustment in my opinion. But problem could be caused by other things as well.

Do you think its worth a shot changing the filters around to fit right onto the carb?

It seemed like it was weird that the problem only happens at higher speeds, thats why i didnt think it was a fuel problem, and more of an air problem.

Those filters are hanging out there in the wind and sucking alot of air especially at higher speeds. Moving them to the carb puts them behind the engine, and cuts down the direct airflow.

The guy i bought it off of mentioned that he had the same filters on his other bike, but they were mounted to the back of the carb...so i think he mightve re-jeted my bike the same way as his and never changed the air filter arrangement.

Does any of this make any sense?....Im handy with tools, but im no mechanic specialized in troubleshooting...ahah

So solid bolts to plug those AI holes?...I guess i should order them from newspeedmaster.com?

Thanks alot for your help man

Tom

Yes, sir, solid bolts in the old AI slots. I had to install a set in mine to replace the "rat condoms" the original owner used to plug the AI tubes. I think if all he did was cut off the tubes and you see a "hollow bolt" next to the spark plug I'm thinking it might be sucking too much raw air into the exhaust side at high rpm and boogering your intake balance.

alright im guessing he kept the stock hollow plugs after he cut the tubes and just threaded another bolt into the top of that to plug up the hole. I understand now..ahah...I guess im ordering those bolts off of newspeedmaster.

But if they were still plugged up, that cant be the cause of my higher speed problem.

Oldroadie do you have any thoughts about my idea of moving the air filters?

If I understand the filter arrangement they're facing forward so that at high speed the drag actually causes a bit of a vacuum around the base of the filter and that might actually reduce the intake volume. Personally, I'd pull a spark plug and look at the tip and see what kind of mixture you're really burning. And, if he put a bolt into the AI tube how is it really sealed ? Enough air to booger the intake mix could still seep in past the threads...

Easiest way to find out if it's the horseshoe things is to pull em off and find out. Should only be 15 mins work.

I agree. Take 'em off and test ride it.

I had a similar problem after i installed a freak kit and rejetted. Bike used to break down like it was running out of fuel in top gear at about 3500 - 4000 revs. After days of eliminating things i discovered that the needle jet holder and pilot jet had some holes partially blocked with crap. Cleaned them and blew them out and now all is fine. i then removed the tiny filter at the T junction and fitted an inline glass fuel filter at the petcock. Was surprised that something so minor made such a difference to performance.

Good tip about the filter, that could easily starve the engine at higher rpms. And, after all, a 2003 with 2300 miles? It had to have sat around more than it ran for the last four years increasing your chances of mini-bits of crud fouling the carbs, the filter or both.

Forgot to add, when cleaning out the holes, do not use wire or drill bits etc as they could enlargen the holes and screw up everything.

Last night was the first dry day in a while so i figured i'd take it for a little ride to see what happens in the cooler weather...and it ran alot better at higher speeds and didnt really break up on me until around 85...what could that mean?

I actually have that little filter already installed on my bike...ill clean that out tonight and see what happens. As for taking the carbs apart ive never done it before...are there any links out there that shows this process?

actually are their any pics out there of what the engine actually looks like stock?...because i have so many little modifcations on this thing that its hard to know what the heck im dealing with here...ahah...im assuming the guy i bought it off of was a real bonnevilleamerica.com follower..ahah

thanks alot for the help

Dinqua has everything you need to know and see already up on his web site dinqua.com and there's much more good info in the Tech Vault

thanks alot oldroadie, that dinqua site is awesome. I just heard back from the previous owner about the jetting...He said it was jetted to size 50 main jets right after he put the streetboogie air kit on it. But then he put heat wrap on the exhaust, so he recommended moving down a size on the main and pilot jets...does this sound right?

I tried using the jet calcualator but they didnt have dunstall pipes in the pull down menu..anyone got any ideas?

-streetboogie air kit
-19" dunstall cocktail shakers with 1 or 2 baffles removed
-size 50 main jets

Do you mean 150 main jets? Stock jets are 120-122 and stock pilots are 42. The breaking up and stuttering sound like it's getting too much fuel at the top end (all main jet at that point). I would start by pulling the plugs and checking the color. That will give you a good indication for which direction you should go in.

The guy typed me size 50, but im assuming 150. I pulled the plugs over the weekend and theyre blacker than anything.

waaayyy to rich.
if you are will to tinker this is what you need to do.

drain the carb bowls , remove the carb bowls.
remove the main jets and check size.
remove the pilot jets and check size.
then let us know what you have so we can make more
educated advice.

I think your mains a too large , but not sure about your pilots.
you want the bottom to be just lean enough that it does not
foul up on you in traffic and city riding.
and you do not want the main so big that highway riding
fouls the plugs ( which you sould like ).

also, check the mixture screws ( how many turns out )

alright, that makes sense to me...Ive been reading up on the dinqua site so im getting familiar with the process..its just a matter of finding spare time to do the job.

do the carbs have to be balanced after you change the jets out?

and whats your best guess on the jet size? I cant just take this all apart and leave it there while im waiting for an answer off this forum..ahha...the guy told me he changed the jet size, not the pilot size...he didnt say if he turned the mixture screws..what do you think?

You can still ride it, just take it apart to get the info and put her back together.

Man, I can barely find time to ride the thing..let alone work on it, and youre telling me to take it apart twice?...haha...

I mean im aware of the fact that i might need to take it apart a couple times to get the right setup, but if im gonna take it all apart, im gonna go in there with an idea of what i want to change it to first..haha

it is hard to say about jets , as I am not sure of the pipes you have.
but my friends bike has the stock air box with K&N stock
replacement filter, stock pipes completely gutted.
and 150 mains jets are about perfect.

I would sugjest that you start with 42 pilots ( stock )
turn out 3 turns.
150 mains and put 2 shims ( brass or stainless washers )
under the stock needles.
then take it for a ride ( not to long ) and see how it goes.
then let it cool and check the plugs.

now these are just guesstimates , without knowing what you
have in there now.
if you can get several sizes of jets and step down 5 to 10
from what you have that seems to be making it too rich.
if you go too far too fast you could get too lean .

i dont get it though, your friend has the air box with a k&n, stocks drilled out, and 150's are perfect. I have no airbox with k&n streetboogie kit and shorter pipes, and the 150's arent working for me...is this because of the mixture screw settings you think?

i have a bunch of jets that came with the bike, i just never read what sizes i have and all that...but what do you think try 140, then 130 and work my way down?

I ripped off the a/I system. Freaked it out and put on some better pipes. Then I took the bike to a Dynotune guy. There we did 4 runs on the dyno. We ran it and looked at the result at every 000 revs, right upto to 7ooo revs. After each run we made some changes to the jetting. After the 4th run it was running like a dream. Pats jetting grid it very good but it’s a guide to get you in the ballpark. Some guys use the “ Butt dyno” which will also be close but not spot on. If you really want to get it right put it on a Dynotune. Every bike runs a little different.

you make a good point...how much did it cost you when it was said and done?

ill try to find somewhere near me and see what the prices are....there is a certain pride to doing it yourself and learning all this, but then again i'd like to have the bike run the best it can.

now are there specific places to have it dynotuned that just specilize in motorcycles or triumphs?...any links or anything?...im from NJ

Cost me about $400 Kiwi dollars, and took about 3 hrs all up. Pride dont make it run right. Carbies are tricky. The guy who did mine let me hang around and I asked plenty of questions. I wanted it to run as well as it could. Once its done you should have to only balance them now and again.

first your pipes may have more back pressure with any baffle
in them , second we can not be sure what jets are in your bike
pilots or mains?

I recently tuned a speedmaster that had me confused until
I dicovered that it had 48 pilots ( way to big )
and the mains were way to small.
but after the trial and error and finding what was really in
the bike we got it set good and the owner is happy.
ahh what fun we all had at the GA rally.

I do not know what affect your pipes are having so I have to
guess until I know what you have.

If you take it to some one with a motorcycle dyno they
will get it done right and you will be happy with the performance.
other wise its the butt dyno , plug read and trial and error
with the jets until it is right.

does this make any sence or am I rambling again

No youre making complete sense, i just gotta find some time, and learn how to do this crap...or pay a guy to do it for me with a dyno. i'd like to fix the problem myself cause first youre taking it for the carbs, next your taking it for something else...its all a money pit really..if i learn it myself i can just waste my money on the overpriced parts instead of the overpriced labor...haha

Alot depends on altitude as well whats good for me isn't always good for you. I run 155 main and 48 pilot and is just about perfect but I am at almost 2,000 feet above sea level with the Freak kit , AI removed , gutted stock pipes. You may in addition to all the above advise want to pull your pipes and see if the reducer cone was left in. If not get a small baffle to give you some back pressure. I don't know your elevation but 150 mains with what you have described doesn't sound far off might want to look at your needle to see if maybe it is shimmed too much causing a rich condition since more shims = more fuel with the same size jet. I would also remove the horseshoe bits and just put the K&N pods on.

alright, ill check out the shims....theyre in there stock arent they?....can you just remove the shim and have none?

yeah those horseshoe things are kinda bulky, when i first got the thing they were falling off while im going 50 down the road....thats not cool at all..ahah

there are no shims stock from the factory.
the needles just rest in the bottom of the slides
under the springs.

and yes , I think the pods on the carbs is a better idea.
the horseshoe idea of ram-air is ok ,but not sure on the actual gains.

so I just called around and i cant find anyone that works on triumphs...haha...but the guy down the road will charge me $25 for a dyno run. If I get the print out information, and it tells me that Im running lean or rich...Im still stuck in the same position as to what mains to use and all that right?

can anyone point me in the right direction to find a place that specializes in triumphs around the NJ PA area?

if you do get the dyno run, you will have a better understanding
of where the problem is.
pilots or mains.
witch will help determine the direction of tuning.

sorry I can't help with the shop , I do all my own work in
my little 2 car garage.

alright, i got the carbs open last night. I have 137.5 main jets and 55 pilots, and no shims. Im assuming that the pilots are the problem right? Im thinking I should start from scratch on the pilots and go with 42's right?

also when i was putting it back together i noticed gas was pouring out of my air filter when i turned the petcock on...what the heck did i do?

I followed dinquas steps except for 2 things.

i didnt drain the bowls before removing the screws, because i didnt have the right size allen wrench.

and i couldnt get the needle out with pliers so i just pulled the whole needle assembly from the top of the carb and turned it upside down to get the needle to drop out. It went right back in with no problems

So whats the problem?..haha

stuck float if gas is pouring out. The floats shut the gas flow off to the carbs when they fill. Maybe one of the little float jets was joggled loose when you tipped it over and shook it, by the way, don't do that!

are there any pictures anywhere of where the float jets are located so i can check them?

any advice on how to go about fixing the problem?

Thanks for the tip, ill have to get some better needle nose pliers.

The float needle is right behind the main jet.

Ok ,
way to rich on bottom and maybe lean on top.

I would start with 42 pilots , 3 turns out on the mix screws.
then take it for a ride. if it has trouble getting over 80 or 90 easily, it is to lean on top.

as far as the way you pulled the needle , that is the way I
do it.
just be careful with the rubber diaphram it is delicate.

as far as the gas from the intake , when I had that problem
it was a bad float.
yours may just be stuck or you may have something out of wack when you put the carb back together.
pull the bowls and check to see the float is moving freely.

I have found bikes with to large of a pilot can idle ok and
pull well just off throttle but lack power at the top if the
main is not large enough.
the carb has to much fuel fuel to burn when you open the
throttle it pulls hard because of the added air.
but if the main is to small it burns of the extra fuel from
the to large pilot and leans out on top .
drop the pilot and raise the main.

I didnt have enough time last night to take it all apart again cause it was getting dark..(no garage)

but I definately think the floats stuck or the needle fell out, cause it worked fine until i opened it up, and it is my first time taking apart a carb..haha

Ian's gonna give me 42 pilots and im gonna start from scratch, keep the 137 mains and see what happens...if it dont work out, i got 140's and 144's to try.

What youre saying makes perfect sense snekeptp, i guess the guy before me increased the wrong jet when he jazzed it up.

Ill report back when I open it up again.

P.S. Thanks to all for your help. This site has really educated me alot over the last couple weeks. You can actually see my general knowledge progress just by reading this thread from start to finish.

I had a bike that did that...problem was getting too much fuel! In top gear you are pullling the throttle more but the engine is not doing enough revs to burn it off. Is it worse if you are going up a hill and better if you are going down a hill? Mine was fine until you put in into 5th and tried to keep accelerating but if you dropped it into 4th and kept the same speed it was fine. Found out he float level was wrong in the carb.Sorted it out and it was fine then.

Steve
Steve