Stihl 040 wont start

[goatroper]

My 040 seems to be getting oil in the crankcase causing very high compression. I pulled the plug and pulled her over a few times,replaced plug. Wants to start almost starts but doesent. Any ideas? Does anyone have a shop manual for this saw? Thanks Jeff

 

[wigglesworth]

My 040 seems to be getting oil in the crankcase causing very high compression. I pulled the plug and pulled her over a few times,replaced plug. Wants to start almost starts but doesent. Any ideas? Does anyone have a shop manual for this saw? Thanks Jeff

Most likely the case gasket has torn or been displaced and is leaking bar oil into the crankcase. If that is the case, the only fix is to do a complete tear down.

 

[dh1984]

Most likely the case gasket has torn or been displaced and is leaking bar oil into the crankcase. If that is the case, the only fix is to do a complete tear down.

:agree2: with wigglesworth on this one the only way to fix this problem is a complete tare down. and if you don't want to fix it your self just send it to me and i'll fix it for you for 5 bucks an hour and plus parts

 

[hotshot]

Oil Pump o-rings

Common problem in these old saws. You only need to pull your oil pump out of the front of the saw & replace the two O-rings which are 6x1.5 mm. McMaster-Carr stocks them in Viton materail that work great!

Also suggest you run a crankcase pressure test as the oiler knob adjuster O-ring is probably leaking too.

 

[wigglesworth]

Common problem in these old saws. You only need to pull your oil pump out of the front of the saw & replace the two O-rings which are 6x1.5 mm. McMaster-Carr stocks them in Viton materail that work great!

Also suggest you run a crankcase pressure test as the oiler knob adjuster O-ring is probably leaking too.

I had not heard of that problem, but hey, I learn something new every day.

 

[djmercer1]

Common problem in these old saws. You only need to pull your oil pump out of the front of the saw & replace the two O-rings which are 6x1.5 mm. McMaster-Carr stocks them in Viton materail that work great!

Also suggest you run a crankcase pressure test as the oiler knob adjuster O-ring is probably leaking too.

more common was the rubber ring on the oil pump on the lay down models (1110 and 1111 series)... i have the tech info for the 041 and 051/075 units...