Chain Saw Masacre....

A buddy has a ~18" McCulluoh chain saw it's a '92-93 model....

it quit running, starts but then dies out and won't restart....

not fuel, not carb....has NO spark, new plug...

the magneto coil, a small 2 pole white thing next to the spinning magnet wheel/flywheel measures 875 some odd ohms, yet I can not get a spark outta the plug.....plug is new.....

I can't figger if the coil has continuity like that it still maybe have shorted turns internally.....

anyone know anything??? he can find a part out in California, but it's going to cost some 85 bux to get it....


:fishing:

I don't know,i own a Stihl chain saw for some 12 years now,never a problem put gas and oil in it and away it goes,those Mac's are old technology IMO
Case closed ! :shocking::stirpot::crutches:






:harhar::harhar::harhar::harhar:

If it has a kill switch make sure the wire isn't getting pinched somewhere.

easyasone2three said:

If it has a kill switch make sure the wire isn't getting pinched somewhere.

Click to expand...

IT SEEMS as if the kill sw OPENS the circuit...strange, but it would save the coil...I looked around for another contact for like points....nothing...no sense in pulling the wheel...

:crap:

I would be willing to bet that the kill switch closes the circuit. A pinched wire will shut it down.

It sounds like the flywheel magneto and stator is working. Loose ground?

Did you get any water in the electrical connectors when you were cleaning it up?

How is the compression? Those 2 cycles need a new piston and ring about every 25 hours or they will quit running.

easyasone2three said:

I would be willing to bet that the kill switch closes the circuit. A pinched wire will shut it down.

It sounds like the flywheel magneto and stator is working. Loose ground?

Did you get any water in the electrical connectors when you were cleaning it up?

How is the compression? Those 2 cycles need a new piston and ring about every 25 hours or they will quit running.

Click to expand...

TWO wires off the coil, one goes to the switch, open circuit to everything but that other switch terminal....and the switch in the RUN position seems to be shorted to ground....weird, I know...but that' what is, is....went back over it a bunch of times...so it boils down to the coil...I can't figger anything else...

so gotta ask....

Disconnect the wire from coil to kill switch.
If still no spark then the coil is bad.
Coil gap should be around .012

010752 said:

Disconnect the wire from coil to kill switch.
If still no spark then the coil is bad.
Coil gap should be around .012

Click to expand...

Thanks man, I tried it every which a ways....no go....

:sos::chinese:

Gene,

Did you ever figure this out? I have a buddy that works on these things and says that if it's startring at all it's getting spark. He says that its tough to detect spark because the ground is weak. Grounded at the base gasket. To check spark clip to the chain for a better ground.

When choked it will dump enough fuel to start but not continue to run. Take mixture screws out as they clog up and just blow them out with carb cleaner. I don't know, hope this helps.

NO, Johnny took that saw with him he was trying to get a coil....

he determined to fix it.....I think like any small engine these days....especially with what happened to Mac everthing seems to be a pitch it item these daze...

Haven't heard a word since Saturday....

:beer: