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, 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

[rmlee61]

I recently got an XL-12 running and my main issue wound up being the carburetor. It would keep flooding and pour fuel from the muffler. Before I got to that solution my saw would start, rev on its own, and die. I replaced both crank seals and that seemed to solve that problem. Other than that, if it was me I’d check the fuel filter and make sure it isn’t clogged. I’m new to working on these saws but I’ll try and help if I can. I’m sure more experienced members will chime in and help you get it running.

[edju1958]

Jan 23, 2023 19:16:34 GMT -5 rmlee61 said:

I recently got an XL-12 running and my main issue wound up being the carburetor. It would keep flooding and pour fuel from the muffler. Before I got to that solution my saw would start, rev on its own, and die. I replaced both crank seals and that seemed to solve that problem. Other than that, if it was me I’d check the fuel filter and make sure it isn’t clogged. I’m new to working on these saws but I’ll try and help if I can. I’m sure more experienced members will chime in and help you get it running.

I agree,start with the simple things first like a fuel filter & spark plug.

[fordsoll]

The compression is 95 and it should be 130 to 155 i dont know how low these can get before they are junk. the spark plug is always wet when i take it out, tommorow i will put an inline spark tester on it and run it to see if the spark stops when it dies. Possibly the magneto is retarded enough that past a certain rpm it wont run? the crankcase seals being bad would cause the saw to suck in more air which would cause it to rev higher on its own the problem is it doesnt even rev up that high when it does run

[edju1958]

Jan 23, 2023 19:48:46 GMT -5 fordsoll said:

The compression is 95 and it should be 130 to 155 i dont know how low these can get before they are junk. the spark plug is always wet when i take it out, tommorow i will put an inline spark tester on it and run it to see if the spark stops when it dies. Possibly the magneto is retarded enough that past a certain rpm it wont run? the crankcase seals being bad would cause the saw to suck in more air which would cause it to rev higher on its own the problem is it doesnt even rev up that high when it does run

If your compression is only 95 psi,that's your problem.The compression is so low that it can't fire.A new set of rings would be in order,but it'd depend on if the piston is scored or not.Pull the muffler & have a look.The rings could also be stuck.

[rmlee61]

I put a set of rings on my saw as well. It brought compression up enough to notice a difference. +1 on what edju said.

[fordsoll]

I pulled the muffler and the piston looked terrible so i pulled the cylinder and only one side of the cylinder and piston is bad the intake side looks normal. The piston has really deep gouges and i can feel gouges on the cylinder wall to im suprised it didnt seize the the crankshaft also has a bit of play in it. i believe this repair is beyond a set of rings it would need crank seals crank bushings/bearings probably a new wrist pin cylinder piston and rings and even then it might still have carburetor and spark issues so i might just use it for parts for a different saw.
Thank you everybody

[edju1958]

Sorry to hear that it's in such rough shape.Yeah,saving it as a parts saw is a good idea.