Dolmar Chainsaw refuses to start

[pioneerguy600]

Too much compression, is it flooded?
You should pull the flywheel and look at the key while you are at it.

Wish that saw was here with me ,I would have it running pronto. No saw has ever taken me more than a couple hours to have it running, only then they would need a total tear down,replace a crank or case gasket, only takes 1.5 hours or less to change out a P&C

 

[eugene89us]

@pioneerguy600 Do you want to come visit us here in beautiful, 110F, 99% humidity Mississippi? Or come on over to beaches of Florida, I will meet you there as you vacation and bring the saw with me. Haha.

 

[pioneerguy600]

@pioneerguy600 Do you want to come visit us here in beautiful, 110F, 99% humidity Mississippi? Or come on over to beaches of Florida, I will meet you there as you vacation and bring the saw with me. Haha.

I would really like to but there very serious gentlemen at the border that really don`t like me , entering your country is something I seldom do. Fixing mystery saws is something I really like to do and often get the chance to do this from saw owners all around me. Getting a saw dropped off that won`t start no matter what was previously tried really gives me a chance to use my noggin for something other than a hat holder.

 

[lone wolf]

Wish that saw was here with me ,I would have it running pronto. No saw has ever taken me more than a couple hours to have it running, only then they would need a total tear down,replace a crank or case gasket, only takes 1.5 hours or less to change out a P&C

Buy it ! So do I actually it would be fixed fast.

 

[pioneerguy600]

Buy it ! So do I actually it would be fixed fast.

I am kind of maxed out on saws, I really do not have an accurate count any more, something like 50 work saws and more than 100 collector saws and I still build complete running saws from my parts stash, there are 20 odd saws sitting here waiting for time to rebuild them, have all parts needed to do full rebuilds on them everything from 026`s up to 066 and MS 660`S

 

[ZeroJunk]

There is something wrong with this story. Not sure exactly what.
You can't have compression, spark at the right time, and fuel, and the thing not run. At least long enough to burn up what's in the crank case.

 

[coffeebrk]

There is something wrong with this story. Not sure exactly what.
You can't have compression, spark at the right time, and fuel, and the thing not run. At least long enough to burn up what's in the crank case.

Bad fuel would cause it not to run.

 

[ZeroJunk]

Bad fuel would cause it not to run.

True. The only other thing that comes to mind is muffler stopped up. Happens rarely in saws compared to trimmers and blowers because saws typically run hotter longer. But, it does happen.

 

[coffeebrk]

@pioneerguy600 Do you want to come visit us here in beautiful, 110F, 99% humidity Mississippi?

The OP states he has high Temps and high humidity so an excellent opportunity for water in fuel.

 

[ZeroJunk]

The OP states he has high Temps and high humidity so an excellent opportunity for water in fuel.

Think he has tried different fuel. Maybe pre mixed, or I have threads mixed up.

 

[coffeebrk]

Yes he's tried Motomix and I think he dumped some and bought fresh. Maybe the kill switch??

 

[lone wolf]

Yes he's tried Motomix and I think he dumped some and bought fresh. Maybe the kill switch??

That should have been disconnected, if not already, he should now.

 

[farmguywithasaw]

Did you check spark with a spark tester or a plug

 

[lone wolf]

Did you check spark with a spark tester or a plug

Or a helpers hand?

 

[farmguywithasaw]

Or a helpers hand?

Lol did that by accident a time or two

 

[lone wolf]

Lol did that by accident a time or two

There have been a few times I held one myself, I was so frustrated with the saw ! It wakes you up good.

 

[farmguywithasaw]

There have been a few times I held one myself, I was so frustrated with the saw ! It wakes you up good.

After getting caught up again.
1 test the spark with a spark tester the gap on a plug is not big enough simulate conditions in the cylinder. The gap needs to be bigger at atmospheric pressure.
2 pull the flywheel and inspecte the key. It Doesn’t necessarily need to be off by a mile for it not to want to run.
3 and the thing I suspect most of all is you have a massive vacuum leak some place. My thoughts are cylinder base gasket or the case gaskets. Or one of your seals is completely blown out. The saw has to make vacuume to suck in fuel air mix but it also needs to be able to pressurize the lower crank case before the transfers open. This forces fuel air mixture up into the combustion chamber

 

[ZeroJunk]

Check muffler screen if it still has one.

 

[eugene89us]

Thanks, gentlemen (and ladies if any here) for great suggestions. Yes, I first suspected and still suspect fuel to have been bab due to even my tank of saw Stihl MS 261 stalling at idle on the "fresh" fuel I got. I bought definitely fresh 93 fuel with ethanol after that (which pains my heart, but I cannot trust non ethanol station anymore) and I splurged $39.99 for MotoMix (which gave me even more chest pains). I know fuel is not to blame. I know the compression is not to blame. I know the muffler is not to blame because I verified that spark arrestor is clean - which it is, it still has shiny appearance since it is still new. And I tested starting with muffler off completely, so muffler possibility was eliminated. Two carburetors pretty much eliminates carb issue. I also gave one carb extremely good cleaning and testing. I still think I have a massive air leak. The saw died like it ran out of fuel, all the lines are patent and there is plenty of pressure in the tank that builds up almost instantly with cap closed. There is never vacuum there. With pre-carb delivery checked and carb itself cleaned and tested with alternate carb, I think the perfectly running saw stopping inside the cut was likely due to a vacuum leak, because I do not feel vacuum forming when I close the air filter hose with my thumb. I have received Mityvac vacuum and pressure tester, I just need to find time to test pressure and vacuum. How much PSI and how much inHg do I need to pump to safely test seals and gaskets? I think "Married with Engines" You Tube channel has a few videos posted, I need to check how much she pumped hers to.

 

[eugene89us]

Did you check spark with a spark tester or a plug

Checked spark with a plug, don't have in-line spark tester. Checked it with 3 coils - original high speed, original gently used red 204 coil (low speed, but compatible), and compatible brand new Chinese 204 coil. All spark the same. Does anyone have a timing light they may be willing to lend me or recommend an inexpensive one? I can check to maker sure timing also matches. I really don't think timing is an issue, but if vac test fails, I will have to take flywheel off to determine which seal leaks, so I will check in one swoop. Now the goal is to check to see if leak or pressure is the issue, if cylinder gasket, it will be a simple fix.