Higher idle when warm?

Inked Monkey

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My bobber is running great, but after it warms up it doesn't like to come back down to idle. The carb linkage is returning all the way back to where it belongs, but the motor revs up? I have to let out on the clutch a little in order to bring the rpms back down. It's an 80 motor, with pods and drag pipes. I've rebuilt the carbs and went up 2 on the pilots and running 142.5 on the mains. It runs badass throughout the throttle. What should I check?

Thanks in advance
 
I had a similar problem on my first bike. I looked everywhere for an air leak and couldn't find one. It turned out the exhaust valve was too tight, making it act like a small air leak.

Simply adjusting the valve clearance properly ended about a month of head scratching and working on the carb. Changed it from a barely rideable bike into a perfect running one.
 
I'll check for air leaks first. I haven't adjusted the valves before or the chain. It runs awesome, so I didn't think to do it. I'll have to read up on it and check em.
 
You ought to check the valve clearances first; because you need to do it anyway, and it might save you the looking for leaks, etc., like I did.
 
"Where can you get that "special 4mm tappet wrench" that the tech articles talk about?"
Don't worry about it.
the 650 valve adjust is really easy peasy. an offset wrench for the nut is nice but not needed either. If you don't have a set Use the "look at the money I am saving on this DIY valve adjust" and get a set of metric offset wrenches. I use them more than any other wrenches I own.
PS always set the valves and adjust the cam chain then sync the carbs.
 
You should check the cam chain tension first, and often, every oil change is good. This keeps the valve and ignition timing right.
 
Found the culprit! My left carb's vacuum plug on the boot was torn and almost completely off. I replaced both of them with some fresh rubber and went ahead and changed the clamp bolts to allen heads. She's running great again.

Thanks everybody
 
On the valve adjuster, you can screw the adjuster up out of the rocker arm. With it out grind the little square nob off, cut a slot in the end with a dremmel tool cutoff wheel.
Now you can use a straight screwdriver to adjust the valves. No special tool.
 
I just use my fingers and a 12-point wrench. The locking nut doesn't seem to want to change it on my bike. All the cars I've had that needed this were the same way.
 
Oh yeah, do it, you know you want to.
Cam chain adjust and valves every time you start in on a bike, and before the carbs.
 
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