Trying to solve the broken throttle plate mystery, please help us out.

Broken throttle slide plates seem to be a new epidemic. Some new replacements have failed very quickly although the original may have lasted for years and we wanna know why. There are a few good theories bouncing around and if we put our heads together we can probably figure this out. Maybe someone out there already has, let us know.

What we see so far is the bottom corners of the plate are breaking away apparently due to flexing or vibration. The plates show hairline cracks around the circular indentation before they fail. The rubber O-ring on the back of the plate has a top and bottom. Installed upside down, it doesn't offer as much cushion between the plate and the slide.

Is it plate metal fatigue, carb body wear causing increased play for the slide, do we need to replace the bearings in the little slide wheels, rubber O-rings on backwards, or more frequent backfiring due to engine mods that is causing the problem?

If you had a plate break I'm asking that you take a minute and answer a few questions.

1) How many miles/how old was the bike when the plate broke?

2) Did the left or right bottom corner break, looking at it from the airbox side?

3) Did you make any mods to the bike recently before the failure that may have leaned it out or increased backfiring?

4) Did the broken piece stay for a visit with the piston and valves or just pass through?

5) Did the new replacement plate fail sooner than expected?

6) Did you notice which way the rubber O-ring was installed on the new plate?

7) Have you checked the new plate for hailine cracks lately?



Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now