Throttle valves are hard to move.

[maaah]

In both my engines (657x in a 1995 speedster), the throttle valves are hard to move. i can turn them by hand, but the spring cant take them back to idle position.
Is this a common problem? And i would be glad if someone could tell me the best way to fix this.

//Magnus.

 

[CaptSteve]

This is not a common problem, it sounds like your carbs are dirty and the butterflies are sticking. Spray some carb cleaner on it and wipe it down.

 

[Dr Honda]

If they are stuck that bad... I would pull the carbs, and clean them properly.

As above... it's not a normal issue... and since it's like that on both of your toys... I would think that it may be corrosion. (are you playing in salt water?)

 

[maaah]

I hawe now pulled all carbs, and both rear carbs are stuck. Both front moves easy. It seams like there are a plastick bearing along with throttle shaft that is seized, maby by corrosion around it?
I am thinking about puting grinding paste (Dont know the english word for it) on the shaft and turn it until it moves freely, is that a bad idea?

 

[maaah]

Grinding paste maked it worse since the fine corns got stuck in the plastic. The solution was the dremmel, a really fine grinder and low rpms fixed it quite easy..

 

[Dr Honda]

In the USA... that's known as "Lapping Compound." It's an abrasive paste to fit parts.

Glad you got it sorted out.

 

[Chester]

You would have been better off replacing the plastic bushings and cleaning out the corrosion that was making them tight. The corrosion will keep growing. Do you ride in salt water?

Chester