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Discussion Starter #1
hi.. i have a 77 cb550 four cyl. i went out for a ride in the sun on sunday for an hour or so.. and suddenly it was like i had a sticky throttle.. or something..

symptoms:(in nuetral) rolling the throttle a quarter inch would make the RPMs ro up to 5 or so grand and stay there for a second or two before receding SLOWLY.
note: the throttle cable pulls back like normal.. and sits at its regular resting place..

it makes for horrible shifting cuz after i throttle up, and depress the clutch the rpms climb for a second or so then i can switch or she gets real jumpy..

i examined the throttle cabel whislt rolling it and it barely needs to move before the engine revs up..

i called a buddy and he said if its not the throttle cable it might be rubber seals in the carb. which would possible indicate that its time to rebuild the carb..
any ideas.. ?? i'd rather not get dirty with the carbs...

thanks for any input..
 

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Jester666 said:
sounds like we have similar problems:
http://www.bcsportbikes.com/forum/showthread.php?t=65193&page=2

treat it with some carb cleaner first and foremost.
If I figure out what's wrong with mine, I'll put it up in myu thread, so keep an eye out.

Don't put carb cleaner in a bike with rubber diaphrams . It causes the rubber to swell. I've seen this a few times . The only way to clean carbs is too take them apart.
 

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5thgear said:
Don't put carb cleaner in a bike with rubber diaphrams . It causes the rubber to swell. I've seen this a few times . The only way to clean carbs is too take them apart.
hmm..
what do you use to clean it besides carb cleaner?
specifically, what would you use to clean the diaphrames and so on?
 
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5thgear said:
Was it sitting all winter, It sounds like one of the carbs slides is stuck.
it wasnt sittin all winter.. but it hasnt been riding on a constant basis prior to last weekend.. which on sunday, is where she began this problem.. which hasnt let off yet.. in fact it might be gettin worse..

i was cruisin down fraser highway (downhill!!) and she began boggin out around 4000rpm..
im thinkin its borderline gettin flooded??? i dunno..
i'm officially confused.
 

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It's either a stuck carb as Bill says or you've gotten a crack in one or more of the rubber joiner manifolds that connect the carbs to the engine. An air leak will make the mixture run lean and a lean setting will make the rpms hang up there and only fall after a couple of seconds.

Ditto on the note that the ONLY way to clean carbs properly is to pull them apart. Just squirting carb cleaner down the throats won't reach the parts that need the cleaning. Do it right or don't bother. There's about a dozen small and extremely small passages in any carb that tend to gum up if the gas is allowed to dry out. Squirting carb cleaner down the throats without any dissassembly won't do anything for any of those passages.
 
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awesome. thanks for the info.. im gonna pull her apart this weekend and have at her..

thanks gentlemen.
 
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