Topic: Hanging Revs when not moving

[MotoMartin]

It'll idle down to whatever I set the throttle stop adjuster to, but it has the strongest smoothest idle at an indicated 1,400 rpm, I know it's a little high but lower without the clutch pulled in you get the old rattling sounds.
I forget if lean is in or out - right now I have the air mixture set to 2 turns out - it used to be 3 1/2 turns out when I first got the bike. If it is the mixture screws, how does blipping the throttle bring the idle down? You'd think it would just rev higher.

[TwoTired]

Are the carbs vacuum synced?

[MotoMartin]

I've attempted to sync  the carbs with a mercury manometer. I can get them fairly even then I apply more throttle and the revs take off and when I bring the revs back down the readings are uneven again. The #4 cylinder in particular, a slight turn of the adjuster makes a big difference, but it doesn't stick, next time you rev the bike the reading will be low again.....
Could the accelerator pump effect the readings? The #4 carb has a much weaker squirt than the other carbs. Not sure why that would make the bike rev higher or why a quick blip would bring the revs back down.

[mystic_1]

I've attempted to sync  the carbs with a mercury manometer. I can get them fairly even then I apply more throttle and the revs take off and when I bring the revs back down the readings are uneven again. The #4 cylinder in particular, a slight turn of the adjuster makes a big difference, but it doesn't stick, next time you rev the bike the reading will be low again.....
Could the accelerator pump effect the readings? The #4 carb has a much weaker squirt than the other carbs. Not sure why that would make the bike rev higher or why a quick blip would bring the revs back down.

The accel pump only comes into play when you're actually turning the throttle.  It does nothing when you're holding steady throttle or idling.

Regarding your sync problem, check for loose or worn hardware, or air leaks, would be my guess.

mystic_1

[MotoMartin]

Update:
I adjusted the fuel air mixture screws to 1 1/2 turns out. When I first rode the bike it was perfect but as the bike got hotter, the revs became higher, blipping the throttle will bring the revs back down, but the hotter the bike gets  -the more the high revs become a problem.
I removed and lubed up the cables, which do not seem to be the problem.
There is still sometimes a small amount of gas coming out of one of the overflows, does this sound like a sticking float problem?

[Flying J]

You can check your float levels by putting a clear piece of tube on the over flow line and holding int up next to the float bowl. Then open the drain and see what level your floats are at. If it is sticking it will fill up until it floods into the carb throat and into the air filtter. You may just have to adjust the idle down as the bike warms up. I adjust my idle when the bike is fully warm, when it wants to idle the highest and sometimes i have to blip the throttle. Thats when i adjust it down to around 1200. when you star the bike next time it may not want to idle because it has not fully warmed up. But just keep on the throttle a little at the stop lights till its warm.
see this thread.http://forums.sohc4.net/index.php?topic=51377.0

[MotoMartin]

I have tried the clear plastic tube on the bowl overflow test and they all seem to be at the correct height. Now one cylinder seems to be less hot than the others, the problems are a moving target. One cylinder has lower compression (not the cooler one) than the others maybe all of my problems stem from that? The bike runs well over 3K revs, but off idle is a bit rough, although when the bike is cold it seems alright. I tried doing a carb sync again today, no real improvement. I think I might start from the beginning again: valves, points, timing, carb...