borna

what's the best way to clean the exhust valve on a 4 cycle engine without taking the valve out?
This is for an old OS FS 60 4 cycle engine, which I think the valve is leaking due to high carbon deposit.

Thanks
Borna

Gizmo-RCU

My Feedback: (27)

I had an old Saito 45 that required this once a year. Remove the exaust pipe so you can look into the port and then remove the valve cover. Make sure the valve is closed so that the carbon will not enter the cylinder.
Take a wooden tooth pick and loosen the carbon or use a paper clip end if it's stubborn. gently start pushing on the carbon and breaking it loose, don't gouge up the chamber while doing this. You can rotate the valve by pushing slightly down and turning with your finger. Use air to blow the material out and carefully inspect and remove until the job is done. This is very easy to do and there is nothing to damage if you are careful. Set the valves when you have the carbon out, put back together and go fly.

scratchonly

I read in a Clarence Lee column that you can dribble fuel injector cleaner down the carb with the engine running. Never tried this.

borna

I have the head out and there are some carbon build up on the valve sit and valve face therefore causing small air leak. So is there any solution that I can soak it in to desolve those gunk? As suggested maybe fuel injector cleaner?

Thanks
Borna