Help needed troubleshooting a Dolmar PS-401

[AlwaysLimbLeft]

I'm visiting my uncle in rural Nebraska and he asked me to take a look at his saws. He has some craftsman  and a Dolmar PS-401. He says he hasn't run 'em in a few years and wants to dice up some railroad ties and cut some firewood, but they're not working. He says he took 'em to a local hardware store who said they were toast and recommended buying a new saw, but that he'd take the Dolmar as a trade-in... My uncle was suspicious and decided to keep his saw. Now he's in luck. I'm in town, I love saws, and I'm fam, so of course I'll take a look... (NOTE: I have no idea who this "dealer" was except that he is not the local Stihl dealer or Sears.)

Well, the craftsman's done.   No loss there as far as I'm concerned.

But the Dolmar... I spent a few hours tinkering with it yesterday.

Status:

• only ~40hrs of running time on it, according to its owner, my uncle
• filter = kinda oily, but I can see plenty of daylight through it. Frankly, I've only run pro saws and am not familiar with these smaller air filters and have no idea how they age
• I changed the fuel, the old stuff was rancid and had sat in there for upwards of three years
• I'm getting spark, but what seems like a weak shock. More on this further down...
• I'm getting at least some compression. When I plug the spark plug port with my finger, it is certainly harder to pull (not a very exact test, sorry)
• I can get it to fire by holding a lighter next to the spark plug port and pulling the pull starter. Better yet - I can get it fire by pulling the pull starter with the spark plug in its boot, but just dangling next to the port (but not every time). However, I do get spark 100% of the time.

My analysis/possible causes:

• the gasket that goes between the muffler and the cylinder is missing. The muffler was disassembled and in a gallon ziplock bag when I first laid eyes on the saw. Apparently the "dealer" or whoever gave it back like this.
  
• Dirty carb. I really don't feel like/have the time to tear it apart, but there was HORRIBLY stale gas left it this little saw. I mean, it was (edited profanity, bad enough to get banned for) green when I poured it out. However, with new gas, I'm getting vapor burping out when I pull start without the spark plug in
• bad seal somewhere? I haven't properly ID'd this on a saw before, but (see 7)
• dirty spark arrestor. Haven't checked this yet. [gameplan for today]
• simply in need of re-tuning. I've tried this a fair bit already, but I am willing to continue to troubleshooting/searching for the right L : Idle ratio... [gameplan for today]
• new spark plug. why not? that always works. [gameplan for today]
• the cylinder is fouled/damaged. The muffler was left off by the dealer and I see what could be some minor scoring on the pistol. It's also pretty gunked (black oily slime) up in there.
• My uncle just needs to buy a new, better saw, preferably Husky or Stihl. They do sell Husqvarna Rancher for $400 in the nearest town.

I apologize for my lack of mechanical knowledge/terms, my knowledge on this subject matter is all  based troubleshooting saws in the field.

[ladylake]

Try dumping a little mix down the plug hole or carb, put it on fast idle or hold it wide open, switch on and see if it will fire. If it does clean the carb or maybe put a kit in it. A Dolmar 401 is a good saw, better than home owner Husky or Stihl saws.   Steve