Stihl 039 Spark Pug Blow Out

[integrityman]

My Stihl 039 has been a real workhorse until recently. The spark plug has come loose and came out with a sudden POP. I let the plug cool off and then tried to screw it back in. Unfortunately the plug will not screw in as it just spins in the threads and doesn't tighten up......I will take it in to the local dealer....but was hoping for some preliminary insight....I'm gearing up for bad news in terms of an expensive repair. Any ideas how much $$$ will I be looking at for a repair?

[integrityman]

ideas anyone???

[AmsoilPower]

My Stihl 039 has been a real workhorse until recently. The spark plug has come loose and came out with a sudden POP. I let the plug cool off and then tried to screw it back in. Unfortunately the plug will not screw in as it just spins in the threads and doesn't tighten up......I will take it in to the local dealer....but was hoping for some preliminary insight....I'm gearing up for bad news in terms of an expensive repair. Any ideas how much $$$ will I be looking at for a repair?


To fix correctly it will be a new piston/cylinder assy. A helicoil just doesn't seem to work in this application well. There are many who do it, but many do not last very long.

[integrityman]

Thanx-

Any idea why this happened? cost of repair?

[AmsoilPower]

Thanx-

Any idea why this happened? cost of repair?

Nope, but seen it several times.

[jkilov]

The problem is that some of those old saws, like mine, have a wery shallow plug hole. There must be like only 4-5 threads holding the plug in place. Just a failure in the material or over-torquing the spark plug can cause problems. Cause the thread is'nt that deep it may be troublesome to helicoil.

I'd give it a try. If your saw is anything like mine, chances are it's a darn good saw. Stihl really put some effort into quality back in the day.