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carb issues, maybe its in my head

Old 08-16-2010, 08:12 AM
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carb issues, maybe its in my head

i went riding with some people the other week, and one of them is an older guy who used to do alot of racing, built motors, and knows carbs better than anyone ive met. ive asked people about him and everyone praises his work and his knowledge so we got to talking. i knew my bike was running a little off and after he took it for a ride and then rode behind me he knew she was running rich. the gurgling and occasional hesitation showed her to be running too fat and he said behind me all he could smell was gas. so he offered to help me out by taking a look at her and syncing the carbs. now i was under the impression my carbs were synced by my buddy who had been messing with them for me. turns out they werent. they needed a full turn on the sync screw to run right. on top of that we yanked the plugs and both were black and looked wet. so we ended up taking out the needles and removed the shims. all 5 of them. left the clip in the 5th position for now.

now the bike runs 100 times smoother. i only rode it last night put about 50 km on it, but shes noticeably smoother and even sounds better, not as deep and gurgly but more angry and happy to be abused kind of sound. i cant describe it, but its different and sounds like its running better. the thing runs so much smoother now, it doesnt seem to want to surge at all at lower rpms, but again i havent tested it for more than an evening so maybe im getting ahead of myself on it. but it seems to me as if shes lacking a little power over 8000 rpm. she felt slower to hit redline in 4th gear than usual. when i talked to the guy about it he said its possible that things were so carboned up in the motor that she was just cleaning herself out. hell the carbs had carbon in them that we wiped out carefully when we had them off. also i was thinking it may be carboned up from the track day, i found after each session she wouldnt idle and would stall when i i let off the throttle and clutched in. likely from running too rich as the plugs showed. so the point of this post, well there is no point, i think its just in a my head and once i give her a good day of hard running she'll clear up and get back on pace, but im looking for other opinions on this matter?

also im not sure why my buddy had put 5 fuken shims on the needles. the only thing i noticed is that with the shims out she pops a little when i close the throttle but when i get back on it again theres no hesitation at all. so im thinking maybe he didnt sync the carbs and was compensating for that with extra fuel thinking it was running lean
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Old 08-16-2010, 08:21 AM
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That sounds like IL4 guy vs V-twin guy (or allround at the very least)... Classic difference...

And the less noticable "hit" up top is most likely the deceptive way the VTR makes power if it's running right or close to right... There is just as much power, it's just that the fat midrange masks it...

On the other hand... It might be that once you have cleared out the carbon deposits, you might end up putting one of those shims back... But no effin way is there supposed to be five in there... Then you are definetly compensating for something else, and should start over to get the whole chain right to begin with...
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Old 08-16-2010, 08:52 AM
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Not good. I would say keep your friend far away from you bike.

Buy a service manual and do it yourself thats the only way to make sure it was done correctly.
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Old 08-16-2010, 10:29 AM
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5 shims, really was that on each needle or all together? Then again I do think most folks run these bikes a bit too rich on the top.
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Old 08-16-2010, 11:15 AM
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Originally Posted by 8541Hawk View Post
5 shims, really was that on each needle or all together? Then again I do think most folks run these bikes a bit too rich on the top.
It seems at that point the needles wouldn't even be functioning, since they'd probably be lifted just about all the way out of the jets.

I argee with Daytona.
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Old 08-16-2010, 11:28 AM
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yeah 5 shims per needle. the guy who just synced the carbs, bill, has made the bike run better than its ever run. when the jet kit was put in originally it ran crappy but the guy wasnt a carb guy, then my other buddy korry set them up 3 times, each time we ran into a snag, the proper pilots werent in my jet kit so we had to order them, and then we had other issues. and now this is the 5th time the carbs have been touched and the bike runs alot better. i need to run it in the daytime to be sure and really get a good ride in on it but last night it felt better than before. maybe it picked up a little mid range and the top end feels like its lost a bit of power as tweety said. i remember reading on here somewhere that you cant really trust the spark plugs too much for an accurate assessment of how the bike is running, any truth to that? or can we safely rely on plugs when i yank them again in a couple days to check their color?
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