Power Washing and Roof Cleaning Forum

Hey i know a little about small engines! (Emphasis on 'a little', hah.)

Was looking up the GX390, because that's the engine i have on my pressure washer, and ran across this thread. Did you ever determine the cause Art?

A starter rope recoiling hard is often a timing issue, and a common cause is a sheared flywheel key. What happens is that the engine fires at the wrong time and pushes the piston back down the opposite direction that you are pulling, which causes the rope to yank back violently.

Here is a video that discusses how a bad flywheel key or camshaft causes this condition, as well as an article that discusses the flywheel key specifically :

https://www.youtube.com/watch?v=jCM9U_hADx8

http://outdoorpowerinfo.com/repairs/flywheel_key.asp

Here is a question someone asked specifically about this condition on a GX390. They discuss several other things that can cause it (bad coil, flywheel key, camshaft).  In his case, it looks like it was the camshaft, but he never returned to confirm.


http://www.justanswer.com/small-engine/6z6by-honda-gx390-engine-will-rip-starter-rope-right.html