Scary high idle....

cmantle1 · New Member Joined: Aug 22, 2009 Posts: 5

I got a 76 xs that had idle issues and i got help on another forum. I gave the carbs a good cleaning and it definently helped, but there is still an issue. The bike will idle at 1200, then just randomly jump up to like 4K and wont go back down until i pretty much take the idle screw all the way out. My first thought was sticky old throttle? but it does this when im just sitting on it not even touching the throttle.
thanks for the help
-chris

Retiredgentleman · Posted: August 24, 2009, 1:58 pm Post subject: Re: Scary high idle....

Here's a few things I would check:

Air leaks such as intake manifolds.

Confirm points gap and timing using a timing light.

Use the "dead cylinder method" to adjust the air/fuel mixture screws(pilot screws). When adjusting the mixture screws, you need to have the engine running on one cylinder at about 400 RPM.

ake sure the carbs are synchronized. (manometer is good for this)

What Happened to 650rider.com?

Yamaha xs650