Posted by Mark on June 13, 2007 at 07:35:56:
In Reply to: HSW 450 A2 posted by Mike on June 11, 2007 at 00:31:12:
What you are hearing is a torsional vibration. It could be caused by a number of things. The engine many have to low of an idle RPM. It should be about 750 RPM. The damper plate on the flywheel may be worn out. It is what absorbs the torsional vibrations from the engine. If you have a gas engine it could be misfiring. It causes the engine to run unevenly and the damper plate can not pick up that much vibration. I have the service/parts manual and repair parts available.