High Idle

Local time
2:13 PM
Aug 11, 2008
Cincinnati, Ohio
All works well on my Happy, 'cept the thing still idles waaaaaay too high. I don't think the throttle cable is causing it, however my next step is to cut the zip ties off and let it hang freely as I test it tomorrow.

I took the previous advice and installed an o-ring in the carb where it mounts to the intake manifold, and I removed the manifold, and put Permatex 1A on the mounting flange and remounted it. Same for the exhaust. The result was easier starting, and notably more power, but it still races like mad when I pull the clutch.

The idle adjust screw has no effect, except it will raise the idle even more when turned clockwise. I can turn it CCW until it falls out, but the idle is still screaming.

When I had the carb off to install the o-ring, I operated the throttle and looked at the slide. It appears to work fine with no restrictions or binding. At the idle position, it appears to have about an eighth of an inch open from the bottom, which I think may be too much. How would I adjust it so it closes more?

it should close completely close when you turn the screw all the way out.... something doesn't sound right.
Hmmmmm, sounds like a cable adjustment. Try pulling on cable housing at the carb and see if it has slack, or if the slide moves immediately. If it has slack, make sure the slide is free to move all the way down. It has a groove and little stud arrangement that can hang it up if not installed properly. Also, if the cap is overtightened, it can bind the slide by distorting the barrel. Oooor, gulp, (blushing in embarassment) make sure the slide isn't installed upside down. *Friend of mine* :rolleyes: did that making it hard to start, and when it did it screamed.

Last edited by a moderator:
My high idle was caused by insufficient slack in the throttle cable. I cut the cable ties securing the throttle cable to the frame, and... voila! Idles like a content kitten. Well, I'm glad I put the o-ring in the carb and sealed the manifold because it needed it anyway.

First long trip today. 30 miles round trip to see Mom. Tightend the chain in her driveway, but no other deals. Oh, my fender tangs broke off. The front vibrated apart after a couple miles, the back let go by the time I made it to Maw's. Gave it a break every 20 minutes or so, and rarely exceeded half throttle (but oh so tempting).

I'm hooked!

Hello Don, I'm glad it all worked out.

You're hooked, huh? I'm not surprised.

Most of us will probably be riding these things till the day we die.

So I'll see you around.