Bonneville America Forums Forums Technical Forums Performance Mods Made small jet change, got big problem

My bike had SS exhaust, with the supplied 132.5 /45 jets. I sold the SS exhaust, and went with short TOR's. I lost a little power, so I side gapped new plugs.... much better. Installed a K&N.... better still, pretty much back to the power I had with the SS exhaust.The plugs were kind of dark so I followed posted recommendations for short TOR'S and dropped to 130 main. While I had it all apart I changed to an air box that I picked up on ebay with the divider cut out of it, and no snorkels. I also cut the hole in the lid that holds the filter out to match the hole in the filter. To say it is running bad would be an understatement. At WOT it falls on it's face an craps out like crazy. None of this makes any sence to me. I have tried 2.5 turns out and 3 turns out.... no difference. Also while I had it apart I pulled one of the slides out to look at it, and see if the P.O. had any shims on the needle. No shims. My fear is that I did something wrong. I just cant believe that a small adjustment could make it that much worse. The sound from the intake when it is "dogging" is so loud it vibrates the seat. My next step will be to put it back like it was with the old box, and jets to see if goes back to where it was unless some one has an idea about what I did wrong. Help........

what do your plugs tell you at WOT?????

get your bike warm...
get your bike up to speed in 5 gear hold it at WOT FOR A FEW SEC'S...
then at the same time hit your kill button and pull in the cluch leaver pull over and pull you plug see what color they are!!!!! if the white go up a main jet size if there dark black go down a main jet size...

please tell us what you find out....

BIKER

does it only happen at wot? how does it run at other throttle positions? check the plugs again and see how it is burning

Frank

Biker, do you get tired of reciting the same thing over and over? Just giving you a bad time, man. Buy us books and buy us books, and all we do is eat the covers.

I'll just interject one thing. Start the WOT test with fresh plugs. If your plugs have any discoloration from your old setup, you might get a confusing reading. I'm speaking from experience.

Regards,
Cody

Somebody posted last week that they reinstalled the needle and the little 5-legged white thingy in the wrong order, which made the bike run like crapola. Could that be the case here?

shoulda left the original airbox in place there KBob...what youve done is allowed the motor to breathe so much easier that your mainjet is too small. Also dont go altering the air inlet in the airbox at the opening for the filter.

When your remove the snorkel you permit alot more airflow, put your original box back in and then see how the bike runs. From there remove the snorkel and take it out again...and see how the bike reacts.

All my problems are at WOT. I bought new plugs after my ride last night, but cold and darkness shut me down. I may have one more chance to ride tonite before the impending winter storm hits town.

The hole I cut in the lid was just the part that over hangs the filter to form a lip for the snorkel to mount in. The filter is sealed. NO offence taken. Thanks for the help!

I knew the air box mods would lean the bike out a little but all my research on jetting said I was already very rich for short TOR's. That's why I made such a small change. Stock is 120-42, and I am at 130-45 down only from 132.5 I just cant believe I am so incredibly lean that it won't run.

One other thing I did that I should probably mention is that I took the TPS off at the carb while working on them, but the coupler is there and everything is back together, lined up and working properly.

You may want to try, just as an easy experiment, Unpluging your tps, being you said you had it off. It may not be adjusted properly. If thats the cause. When you unplug it the bike should run normally again. May be just a tiny bit sluggish off idle. Unplug it at the connector behind the carbs not on the side of the carb..

The snorkel is very restrictive, removing it makes big changes in the motors ability to breathe...thats why your so lean.

You coulda left the stock airbox in place, along with the jetting you had and removed the snorkel and you'd still be lean...( imo )

nope just happy to help some one out...

and yes i alway's use fresh plug's when doing this test..


BIKER

Bob, I would follow biker's advice and get a read on the plugs. I was having the same issues a couple weeks ago. I was split between too rich and too lean, and I was getting all kinds of conflicting advice. Finally biker convinced me that my plugs were telling me what I needed to know, and I finally got it straightened out.

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All my problems are at WOT

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thats why i told you to do that test and don't worry about your TPS i have not had mine hooked up for allmost a year now no place to put it on my mikuni's
people will tell you to do this and do that but it all boil's down to one thing...

WHAT COLOR ARE YOUR PLUGS..

BIKER

you may also want to check the fuel flow.
if something is clogged and you are not getting enough fuel
it will affect wot.
don't forget about the little filter between the carbs.

glad i could help

BIKER

Whut is WOT?

Wide open throttle?

yup

BIKER

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Also while I had it apart I pulled one of the slides out to look at it........ My fear is that I did something wrong.

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Hi Bob,
When you put the needle back in the slide, the needle went in first right?
Sounds like either the needle head is on top of the little crows foot spacer and getting pulled out too far too soon, or, the diaphragm is not seated well under the slide cap.
I drilled my slides out and balanced my carbs once then wanted to test drive it. As soon as I rolled on the throttle, it died. I finally opened the slide caps and reached in with my roach clip (i mean hemostats) to pull the white plastic spacer and noticed the needle head on top of spacer. Immediately I said to myself, "Self, you dummy! the needles go in first". Now, if only one needle is on top of the white crow's foot spacer, this would allow flooding one side while the other side ran the motor.
That is what I'd check next.

I'm Pretty sure I have it worked out, because it ran pretty well when I put in the paper filter. Now if my steep 200 foot driveway wasn't an ice skating rink I would know for sure. The last night I rode the bike I wore a sweat shirt and no gloves. 24 hours later it was freezing rain and 17 degrees. If the bike doesn't run with the 132.5 main back in I'll be looking a little closer at my needles. I haven't drilled my slides yet but I plan too as soon as I get the jets where they should be. Thanks for the input.