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Discussion Starter #1
i tried to search, but for some reason the forum kept telling me to enter key words. i was and it just wasn't working.
Anyway, i recently cleaned my carbs and eye synced them. they felt pretty close. about a week later my 4 gauge carb sync showed up. i installed them and gave it a shot. i set the idle around 1500 rpm, soften the gauges out with the dampen neddles, and adjust all four carbs so the gauges read the same.

the instructions say to check the speed of vacuum change when the throttle is pulled to 1/4. so i then adjust the carbs so the effect the gauges at the same rate. <---this doesn't sound right to me.

so now i have a bike that at very part throttle sounds like its only running on 2 or 3 cyl.

what is the best method to use when syncing multiple carbs? this is the first time ive done it. '72 cb750 btw.
 

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Discussion Starter #2
is it that simple or that hard? from what i've read it sounds like i should just make them all match at my idle speed. is this correct and will it resolve my 1/16 throttle miss?
 

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Well, adjusting the idle is different that synching the carbs. If you've got the carbs synched for 1/4 or 1/8th throttle, leave that alone. Now adjust your idle screws.

What the hell bike are you doing this on, anyways?
 

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I like to adjust them off the idle circuit completely

like say 1/4 throttle

you see...... the throttle valves can all be in synch'd but the idle mixture can throw you off

get all the throttle valves in sync for sure

then toy with your idle mixture with the gauges still hooked up

if I have to sacrifice a nice sweet idle for good torque and horsepower

as well as smooth running under larger throttle openings

I surely will and without any hesitation

keep slugging at them, you'll nail them and I'm sure some of the other more inline fluent guys will chime in with some hot tips
 

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Discussion Starter #5
i didn't even think about the air mixture screws! gaddamn i hate removing that tank though. i guess i'll get around to it this week. if anyone else has any tips please post em.

its a 72 cb750 with a hot cam (high idle)
 

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well if you have a "IV" or portable remote tank....... that can take some of the pain out of getting to carbs on some bikes

I keep two around my shop

one that will do 1/4" or 5/16" lines

and the other one for 3/8"

they hold less than a quart of go juice
 
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