Husqvarna 240

[skippa]

I have a Husqvarna 240. I can get it started but at full throttle it runs rough. It sounds like it is skipping. I have replaced the coil, carburetor, and the insulator, seal and the gasket between the carburetor and the head and nothing has helped. Any suggestions??

 

[SawBawss]

So it runs the same with every part change or does it change a little? Have you checked compression? Might want to pull the muffler as well and take a look at the piston through the exhaust port.

 

[skippa]

It is the same with every change I have made. The compression is good(120psi). I have had the muffler off and the exhaust port looks good as well as the muffler. The piston and cylinder look like what you would expect them to look like. A little wear and tear. The saw was running fine, and the chain came off and stalled the saw, and it has not ran right since.

 

[Paul]

Flywheel key

 

[skippa]

The flywheel has the built in key and it looks good. No movement when the flywheel is in place.

 

[SawBawss]

Have you pressure tested it? Could possibly be air leaks around your crank seals. There is not much left to chase but air leaks. May need to remove the cylinder and check for play in the rod and crankshaft.

 

[skippa]

I usually look for oil on the housing under the crankcase seals as an indicator of a oil leak from the crankcase seals but there is not much there. I vacuum tested the crankcase seals. There might be a tiny leak there. I put oil around the seals and put it under a vacuum and see if it pulls the oil in thru the seal. I could not see it pulling any oil in but when I fired it up after testing, I got some blue oil smoke from it but not much. I have ordered new seals for it and am going to replace them. This thing has really got me scratching my head.