Coil Testing with Multimeter?

[HansFranz]

Update #1: I removed from the saw the "coil" that has the spark plug lead attached to it. (The part shown on the left in the picture above. Is this the "secondary" coil?) This piece has two spade terminals on one end (zero resistance between those) and the spark plug lead coming out of the other end. As best as I can tell, the resistance between the spark plug lead and either one of the spade terminals is 167 Ohms.

Since 167 Ohms is WAY outside the range of either (0.5 to 2.5 Ohms for the primary winding) or (5k to 10k Ohms for the secondary winding), am I safe to assume that this part is no good anymore?

Update #2: I pulled off the coil next to the flywheel and bench tested it. This coil has the laminated iron core and two spade connectors - one spade connector had a red wire attached, and the other spade connector had a green wire attached.
Resistance from the iron core to:
Red-Wired Spade Connector: With VOM meter on the 200k (or 20k) Ohms range: Reading was 18.4 (or 18.16)
Green-Wired Spade Connector: With VOM meter on ANY range - Open circuit / I guess "infinite" resistance

Also, the epoxy on this flywheel-adjacent coil is cracked. (Coil appears to be mfg'd by "Selettra".)

So I'm guessing I need to replace BOTH coils. Would you folks agree? Sorry for all the questions...I'm clueless.

If it helps any, here's a pic of the wiring:

https://i.ibb.co/JmLcnCn/saw-coils.jpg

 

[pioneerguy600]

He's working on a Dolmar with a blue coil though, would be different than the infamous blue coils on a Homelite right?

Differences were in my reply.

 

[Okie]

I now see that your Magneto is a completed sealed unit and no removing from the laminations.

You might still try baking the Magneto coil. You have nothing to lose.
Doubtful but you might try Standard Magneto. You will have to call them because they do have things that are not listed on their site.

You might also trying the wanting to buy section on this site and do a saved search on ebay bay. doing the saved search if with your chainsaw model will get you a email if anything surfaces.

 

[Okie]

Update #1: I removed from the saw the "coil" that has the spark plug lead attached to it. (The part shown on the left in the picture above. Is this the "secondary" coil?) This piece has two spade terminals on one end (zero resistance between those) and the spark plug lead coming out of the other end. As best as I can tell, the resistance between the spark plug lead and either one of the spade terminals is 167 Ohms.

Since 167 Ohms is WAY outside the range of either (0.5 to 2.5 Ohms for the primary winding) or (5k to 10k Ohms for the secondary winding), am I safe to assume that this part is no good anymore?

Update #2: I pulled off the coil next to the flywheel and bench tested it. This coil has the laminated iron core and two spade connectors - one spade connector had a red wire attached, and the other spade connector had a green wire attached.
Resistance from the iron core to:
Red-Wired Spade Connector: With VOM meter on the 200k (or 20k) Ohms range: Reading was 18.4 (or 18.16)
Green-Wired Spade Connector: With VOM meter on ANY range - Open circuit / I guess "infinite" resistance

Also, the epoxy on this flywheel-adjacent coil is cracked. (Coil appears to be mfg'd by "Selettra".)

So I'm guessing I need to replace BOTH coils. Would you folks agree? Sorry for all the questions...I'm clueless.

If it helps any, here's a pic of the wiring:

https://i.ibb.co/JmLcnCn/saw-coils.jpg

Agree:

If you find both replace both. The one with the crack would be the main one to bake, but doing a slow heat bake in the oven I would do both unless you want to do them one at a time just to see if one comes alive so as to get a hint of the bad one.
Moisture gets inside when the epoxy is cracked and baking removing the moisture which causes internal arcing.

For me baking is not a permanent fix but some guys get it too work Ok.
You can review baking chainsaw magnetos on-line. (2=3 hours or longer on low heat of about 150-175F

 

[pioneerguy600]

The Makita Repair centers can get all the parts for the newer Dolmars and Makita`s. They seldom have many parts on the shelves but can order them in just like most dealers do these days.

 

[MacAttack]

Differences were in my reply.

Gotcha, I missed that part.