Another Chainsaw / 2cycle question: Won't hot start?

[CobyRupert]

I have an old top handle Montgomery Ward (McCulllough Eager Beaver) saw I got running a few years ago. Use it for special elevated trimming jobs, occasionally.
New spark plug has less than an hour run time.

It usually starts easily, but if you shut it off and try to restart it doesn't want to.

Could this be a coil (coil gap) problem?

 

[dusty3030]

Just worn and low compression most likely.

 

[BobG_in_VA]

I'm betting if you turn up (open) the high speed carb setting a tad you're issue will go away. Sometimes when the engine is "hot", the gas starts to "boil" and causes what I consider to be the issue of good gas getting to carb...can't hurt to try it. BobG in VA

 

[CobyRupert]

I'm betting if you turn up (open) the high speed carb setting a tad you're issue will go away. Sometimes when the engine is "hot", the gas starts to "boil" and causes what I consider to be the issue of good gas getting to carb...can't hurt to try it. BobG in VA

Yes, it's very sensitive on that aspect. Turning it up helps, but then the saw has no power/rpms/smokes at open throttle. I pretty much have to start it with a screw driver. One setting to start, another to run. Yet if choking it when hot doesn't help, it just causes you to have to give it another 5 pulls (unchoked) before it will think about starting and sputter.

Is there a typical compression range a saw should have, or does it depend on engine size etc..?

I was wondering if it takes a "hotter spark" (i.e. coil) to fire a warm engine than cold?

 

[CobyRupert]

Dusty, Are you saying a cold engine has better compression than when it's warmed up?

 

[dusty3030]

How many rings does the piston have.

 

[CobyRupert]

How many rings does the piston have.

I don't have a clue. I'll see if I can find a parts manual.

What will the number of rings tell me?

 

[dusty3030]

I wouldn't worry about trying to figure that out, you said you had got it running I didn't know if you had it that far apart before.
Single ring would be more likely on the compression part. You can borrow a compression tester and check for sure. Put it on and pull it 3 or 4 times and take a reading cold then put the spark plug back in and run it up to temp and take another reading hot. If hot less than cold my theory if not then something else.
Ideally you don't want to see anything less than 120 or so and 150 or more ideal. Less than 100 it needs some work or retirement.

 

[BobG_in_VA]

As far as rings and compression are concerned, I've always found if a 2 stroke engine (once warmed up), idles good, then it will run good as well....if it won't idle, then you have issues. BobG in VA

 

[CobyRupert]

It starts and idles well, it just doesn't restart if it's warm.