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Discussion Starter · #1 ·
Howdy guys,

I got roped into a project on an 03' to replace a countershaft, I did the job everything went back together fine, the friend of a friend I did it for asked me to re jet the bike while i had it apart. The bike is stock aside from a K&N in the airbox and a billet insert in the stock pipe. I never seen or heard this bike run before coming to me to be worked on. Once I go the motor put back in bike I fired it up with the stock jetting 140/145 with 22.5 pilots. If fired right up and seem to run fine at idle, although I noticed that it got hot quicker than i thought it should. I pulled the carbs off and jetted up to 150/155 and left the pilots 22.5 then took it out for a spin. seems to run well on the bottom end but if you stab it and try to get on it to go it pops and back fires. I took it back to the shop and tweaked some more on a few things tightened header bolts, thought it might be sucking some air in there with new gaskets. It seems to be backfiring on the decel like it is lean, I pulled the plug and it honestly looks a little lean to me there also. My question is that perhaps I got the timing 1 tooth off when i put it back together? would that create the heat I think it has or the lean condition i think I have? Is there a way to check cam timing without pulling the rocker cover off? There is a inspection plug up there but I am not sure how to use it considering the timing marks do not line up with it...

Any help or Ideas?
 

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I am unique
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Howdy guys,

I got roped into a project on an 03' to replace a countershaft, I did the job everything went back together fine, the friend of a friend I did it for asked me to re jet the bike while i had it apart. The bike is stock aside from a K&N in the airbox and a billet insert in the stock pipe. I never seen or heard this bike run before coming to me to be worked on. Once I go the motor put back in bike I fired it up with the stock jetting 140/145 with 22.5 pilots. If fired right up and seem to run fine at idle, although I noticed that it got hot quicker than i thought it should. I pulled the carbs off and jetted up to 150/155 and left the pilots 22.5 then took it out for a spin. seems to run well on the bottom end but if you stab it and try to get on it to go it pops and back fires. I took it back to the shop and tweaked some more on a few things tightened header bolts, thought it might be sucking some air in there with new gaskets. It seems to be backfiring on the decel like it is lean, I pulled the plug and it honestly looks a little lean to me there also. My question is that perhaps I got the timing 1 tooth off when i put it back together? would that create the heat I think it has or the lean condition i think I have? Is there a way to check cam timing without pulling the rocker cover off? There is a inspection plug up there but I am not sure how to use it considering the timing marks do not line up with it...

Any help or Ideas?

Install #25 pilots first and see how it works............
 

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Discussion Starter · #3 ·
#25 pilots in no diffrence.... Now seems to smoke a bit more like it is way rich.. I am going to swap to the 145/150 for mains and see what happens?... any body else have any suggestions?
 

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With the small mods he did to it i would say your on the right track with one size bigger main jets.
 

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have you checked intake boots, there a pain make sure they arn't leaking. Does it have the parking brake rev limiter mod done yet? is it always in the same rpm? just a suggejestion could be one of the 2 limiters.
 

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Discussion Starter · #6 ·
Intake boots are good and I have had the carbs off a few times and make sure they are on well. I checked the rev limiters also, but it is not those this is something different. I feel positive it is in the jetting but after talking ot him he said it ran well with stock jetting before I did the motor work, he thought that it could use to be a tad richer... so I took the 140/145 out went to 150/155 stayed with 22.5 pilots ran crappy both ways, moved up to 25 pilots with 150/155 and still is crappy, I now am going to go down to 145/150 and see what happens, if not better i am going back down to 140/145 with 25 pilots. I have the air screws out 2.5 turns and have not changed needle settings.. Just to make sure larger jet should be in right side carb correct? or the carb with the starter jet?
 

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Discussion Starter · #7 ·
ok after doing the jetting above 145/150 with 25 pilots it made no difference. So on a hunch I put some duct tape over half the snorkel out of the airbox and wala it runs perfect. this leads me to believe that there is a lack of suction into the box to run the slides? I remember a buddy that had one of these that would not run without the air box lid because of suction. the inside of the box lid has been modified on this one but there is no holes in it anywhere, should I go up in the jetting above 150/155 where I was?
 

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I am unique
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ok after doing the jetting above 145/150 with 25 pilots it made no difference. So on a hunch I put some duct tape over half the snorkel out of the airbox and wala it runs perfect. this leads me to believe that there is a lack of suction into the box to run the slides? I remember a buddy that had one of these that would not run without the air box lid because of suction. the inside of the box lid has been modified on this one but there is no holes in it anywhere, should I go up in the jetting above 150/155 where I was?
You could have problems with the slide diaphrams leaking............
 

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Discussion Starter · #9 ·
this is crazy, I had the slides out and the diaphrams look fine. I put duct tape over half of the snorkel and rode it for 20 minutes around my house hay field all over runs perfect. pull the duct tape off and runs like crap...
 

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THen you are set up too lean. Fix onlythe circuits that need it relative to throttle position -

idle to 1/4 throttle = pilot jets and fuel screws
1/4 to 3/4 throttle = needles
3/4 to full throttle = mains.

AND do them one at a time.
 
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