Homelite xl 12 wont stay running

[Fordsoll]

I have a homelite xl 12 and it is insanely hard to start and when it does it runs for a few seconds and dies and it will only start when the throttle is fully open. Earlier i took off the flywheel and discovered that the points were gapped to tight so i adjusted them to .015 and that seemed to improve the quality of the spark but this didnt have an effect on running or starting, while i was in there i also wanted to adjust the timing advance but it would barely move with the three bolts loose but it is not fully at the end of the adjustment i dont know what the effect this would have on running and starting. later i will check the compression but it feels decent. the carburetor has been gone thru twice the second time i replaced the welch plugs and i doubt its the carb because even if i pour fuel down the throat of the carb it is still not starting easy.
Thanks

 

[buzz sawyer]

Did you clean/file the points? Should be shiny metal. What about the gaskets between the carb and housing? If the impulse passage is leaking, the carb won't draw fuel from the tank. What about the fuel filter?

 

[Fordsoll]

I did clean the points i also replaced the gaskets between the carburetor and housing and it is drawing fuel from the tank so i assume the fuel filter is good. The compression results were 95 psi cold dry full throttle and no choke it should be 130 to 155? the previous owner said he didnt run the saw at 32 to 1 because that was a lot of oil so im thinking that is the problem

 

[Vintage Engine Repairs]

I’d guess you have scoring on the piston that is causing drag. Pop the muffler off and see what it looks like on the piston skirt.

 

[buzz sawyer]

I did clean the points i also replaced the gaskets between the carburetor and housing and it is drawing fuel from the tank so i assume the fuel filter is good. The compression results were 95 psi cold dry full throttle and no choke it should be 130 to 155? the previous owner said he didnt run the saw at 32 to 1 because that was a lot of oil so im thinking that is the problem

My brother had one with that low compression. No P&C damage, so I figured the rings were just worn. It would start and run ok, just not much power. He just got rid of it.

 

[pioneerguy600]

Those XL12`s have been around so long that many pistons have been worn down so badly that re ringing them does not bring the compression up all that much. There is a couple of fellows near me that refuse to give up running those saws even though they are well past time to retire them. I have pulled a few of them down and the pistons had .008 clearance but was still running, just low on power. The ring lands were worn so badly could easily slide a .005 feeler gauge blade between the ring and piston body.

 

[Old2stroke]

I did clean the points i also replaced the gaskets between the carburetor and housing and it is drawing fuel from the tank so i assume the fuel filter is good. The compression results were 95 psi cold dry full throttle and no choke it should be 130 to 155? the previous owner said he didnt run the saw at 32 to 1 because that was a lot of oil so im thinking that is the problem

Oil could be a problem if he was using some inferior type like outboard oil at 50:1 but oil has improved since that saw was born and modern full synthetic oils at around 40:1 are good for even those old workhorses.

 

[Okie]

You might try a pressure/vac test of the crankcase before you throw in the towel.

Also to maybe get an idea of the piston/rings worn, bring the piston to TDC, back it down about 1/2 inch and add teaspoon of 20-30W oil then do the compression to see how much the oil increased the compression.
Let us know how much compression difference of the oil test results?
95 is to low. Do you know for sure that your compression tester will read correct high compression on a good saw? (it requires a special tester to read compression correctly on small CC engines)

I've know of guys (some good auto mechanics) overhaul a chainsaw because their high dollar automotive compression gauge indicated low compression and their saw would still would not run after their re-build and their gauge indicated even lower after they installed new rings.

Even though I've seen the little Homies like a Super 2/XL 2 run and cut good at 80ps buti for the larger saws anything less than 130 is iffy.

 

[Fordsoll]

Ok so i took the cylinder off and the piston looks like the piston got red hot on the exhaust side and literally reforged itself im suprised its not seized however the other side of the piston looks normal the piston has really deep scoring and i can feel some on the cylinder wall too i also felt play in the crankshaft i think this repair is beyond rings

 

[joe25DA]

Ok so i took the cylinder off and the piston looks like the piston got red hot on the exhaust side and literally reforged itself im suprised its not seized however the other side of the piston looks normal the piston has really deep scoring and i can feel some on the cylinder wall too i also felt play in the crankshaft i think this repair is beyond rings

The exhaust side is the “hot” side. Intake has the cool, air fuel/oil mix. They burn on the ex side. Scoring on the intake usually means it sucked up some abrasive dust or dirt. I have had lots of the XL12 SXLAO saws. I have a clean SXL I got from the old timer up the road. Has on old school bus in the back yard as his work shop