Small Engines (Lawn Mowers, etc.): Subaru Robin carb problems, mikuni carburetor, oil viscosity

Question
Hi I have a Subaru Robin eh25 with a mikuni carburetor and my problm is the engine surges at idle I have changed the float and th nedle valve also the it will run smooth if you set choke to half closed  

Answer
Hi Robin,

For surges try to stabilize the R.P.M.'s by controlling the governor arm and the carb throttle by
the link up.  You can use your finger or pliers to do this.

If the engine RPM stabilizes then the governor or the  governor adjustment should be adjusted.

Also check the fuel cap.  See if it is venting.

Check to see if the oil viscosity and levels are correct.

Check if there are clogged coolng fins.

Check carb for correct adjustment.

Make sure the correct spark plug adjustment is set.

Check ignition timing.

Check the cylinder head for excessive carbon build up.

After you have completed all the above list get back to me and let me know.

Thanks,


Howard