McCulloch 250 Electrical Help

[Dfib]

Hey everyone.

Nice forum, I spent a good bunch of time on here this afternoon, but couldn't find exactly what I was looking for...

I recently inherited a McCulloch 250 from my grandma's estate. I remember reviving this chainsaw about 20 years ago after my dad bet me it would never run again.

Since I moved out it sat in an abandoned chicken coop, and collected all the nastiness that only a old farm building can provide.

I found it last weekend and brought it home. A good cleaning last night and today, fixed the rewind on the starter, points re-gapped to 0.015", armature air gapped at 0.010", correct plugs (new and old) J8J gapped at 0.025", flywheel touched up with fine sandpaper to remove trace rust, all electrical connections cleaned and scuffed with emery paper.

NO SPARK!

If I hook my multimeter up with one lead on the plug (touching the post) and one on the frame I get readings when I pull the starter, but still no spark.

Could the condenser be shot? Can you test a condenser? Did I get one of the gaps wrong? Coil bad? Any help would be greatly appreciated.

Also wondering about a replacement chain. I counted 65 drive teeth, and I believe the bar is 24", the chain that came off had "58B" on the drive teeth. Does that help?

Thanks in advance!!!
~Smitty

 

[RED-85-Z51]

Remove the points and clean them manually with emory paper, like some 1000 grit stuff. Then install and regap.

 

[heimannm]

Check condenser

You can check a condenser with any multi-meter set on the highest resistance setting if you work carefully. Basically it will appear as an open circuit, but if you switch the positive and negative leads back and forth you will notice a slight "blip" on the meter as the condenser charges and discharges through the meter.

Check the coil by inserting one lead in the spark plug boot and one to the terminal on the coil. Should read between about 2.5K and 5 or 6K ohms depending on which coil. Primary side of the coil will have too little resistance to check easily.

Check the Fluke instructions as well for more information.

Mark

 

[heimannm]

More help?

What pitch chain does the saw have (measure the distance between three rivet and divide by 2), for .404 chain 65 DL would be typical of a 19-20" bar. I am pretty sure my saws with .404 chain and 24" bars have 77 DL, some are 78 which makes it easier to get a new chain on but may require removing a link as the chain stretches.

If you have to get a new chain check the bar carefully with a feeler gauge to make sure of the gauge, many are .058" but there are more than a few .063" as well. I know, I have both in the collection.

Mark

 

[Dfib]

Awesome info!

Now I have something to do on Tues at work.

 

[heimannm]

Where is Lax, WI?

I will be in the Green Bay area next week (picking up three saws I bought off e-Bay), coming up from the Southeast on Monday and going home to the Southwest on Tuesday I expect.

If you are still struggling I could try to stop by and have a quick look. I have a certain amount of experience with similar McCulloch saws.

Mark

 

[Dfib]

I will be in the Green Bay area next week (picking up three saws I bought off e-Bay), coming up from the Southeast on Monday and going home to the Southwest on Tuesday I expect.

If you are still struggling I could try to stop by and have a quick look. I have a certain amount of experience with similar McCulloch saws.

Mark

Thanks for the offer! I'll have a lot of time to play today if work is slow. At this point I'm guessing the condenser needs to be replaced. I should know more soon.

LaX = La Crosse, WI. FWIW

Thanks again,
Smitty

 

[Dfib]

She runs!!!

Turns out the points were more corroded than I thought. A good polishing and she fired off in less than a dozen pulls.

Ace Hardware makes chains so that was an easy fix.

Carb cleaner, engine degreaser, new plug < $10
New chain $15
----------------------------------------------
40 year old chainsaw running again = PRICELESS!

Thanks again for all the help.

Smitty