[Joe87t]

Recently bought a 2 stroke Chainsaw, the previous owner says he bought it brand new and only used it once and then it sat in his basement for years with the same fuel in it. So needless to say it doesn't start.

I drained the fuel, replaced fuel filter, checked fuel lines for cracks, took apart and cleaned the carb. Then attempted to start it, it doesn't even try, however I can smell fuel coming out of the exhaust, so I know its getting gas.

I then put a new plug in it, same thing - doesnt even try... When I put the plug on the housing and turn it over, I see spark so i know the plug is firing... Dont know where to go from here?? Its getting Spark, its Getting Fuel cause I can smell it...

I even sprayed some Carb Cleaner down the carb to try and get it to kick over on its own, even if for just a second and it didn't even try then either.

I took the plug out and spun it over a good 8-10 times and i saw fuel mist coming out of the plug hole like normal... Put plug back in, 1 last try.. Nope still nothing...

Thing thing seems dead as a doornail, unsure where to go from here?

 

[BOSOX]

The new plug may not be firing under cylinder pressure, or there isn't enough compression in the engine itself. Have you done a compression test? Personally, I'd try another spark plug and see if that cures it. Go name brand, Champion, NGK, Autolite etc., some of the generic plugs I've bought last few years at Lowes or HD (to save me a trip to the auto parts store further away) are not reliable.

Keep us updated on what you find! :fing32:

 

[Joe87t]

The new plug i put in i bought new from Walmart, its a Champion and i verified it was gapped properly at .020

 

[BOSOX]

Not arguing the point, but once installed in the engine under pressure some plugs just don't fire. Have you also checked the air gap from the coil to the flywheel, sometimes that could be out of whack too. Without a feeler gauge, a standard business card will usually suffice for the air gap.

 

[Joe87t]

I have not yet checked that, im just leery of a hard mechanical failure given the unit was purchased brand new and used once

 

[Tractor-Holic]

Maybe that one time it was used,it was run on straight gas !..

Seen it happen more than once..

Adding some motor oil to the cylinder via the spark plug hole might raise the compression enough to get it to run,at least for a moment,if low compression is the fault..

 

[Joe87t]

Quick Update: Went out to the garage today and tried what you had mentioned, I sprayed a quick shot of WD40 down the spark plug hole, attempted to start it which was significantly more difficult to pull start (showing theirs compression) but still no bueno.

I then started fiddling around with the Carb abit, I took off the fuel hoses and swapped them with each other, attempted to start it and it FIRED but only for about 1 or 2 seconds then died out... I think I may of had the return line & Primary line reversed?

Ive been unable to duplicate that or get it to start again, but theres progress at least

 

[Greybeard09]

Make sure the plug isn't oil fouled from the WD40.

 

[WNYTractorTinkerer]

Have you cleaned the jets and reset the needles? Start @ 1-1/2 turns open and go from there. I just worked on a bugger of saw like yours yesterday.. Tank was full of varnish and thus the carb.. Found the coil was a mile from the flywheel and fired up and ran great once I reset it.. Tuned it in and back in business..

Next time replace the fuel first BTW..

 

[Ingersoll444]

Quick Update: Went out to the garage today and tried what you had mentioned, I sprayed a quick shot of WD40 down the spark plug hole, attempted to start it which was significantly more difficult to pull start (showing theirs compression) but still no bueno.

I then started fiddling around with the Carb abit, I took off the fuel hoses and swapped them with each other, attempted to start it and it FIRED but only for about 1 or 2 seconds then died out... I think I may of had the return line & Primary line reversed?

Ive been unable to duplicate that or get it to start again, but theres progress at least

OK, it popped... so your on the way, stop and don't make drastic changes!! Re pull the plug as stated... see how it looks. is it soaked?? Clean plug, and try to fire it. You got a pop... it means you are on the way.

Odds are the carb is still cruddy though.. I had one so bad its is was full of black slime, and every time I clean it I get more out... I still haven't got that one to run right... Im just going to replace the carb on it one day..

 

[tomw0]

I'd try the WD40 trick one more time with the fuel/return lines connected the way they are. It's possible adding the WD raised the compression, and you fired on the WD after it dissipated a bit, and then the fuel lines being swapped nipped things in the bud.
You should feel compression whether or not the WD is in there. Red had a test for string trimmers. Hold the trimmer by the starter rope handle. If the trimmer slowly descends, there's not enough compression. It should support itself on compression alone. Try that with this saw. You might find it is marginal. If so, try removing the spark arrestor or muffler and inspect the piston, cylinder and rings through the exhaust port. If you see scoring on the piston & rings, you'll need a couple new parts at least. If smooth, maybe doing the WD40 douche will free up the ring(s) with a few more cycles.
tom