Real time help? Chainsaw troubleshooting needed

[e9999]

OK, here it is:

Stihl 025 (a smallish homeowner type saw) something like 10 years old. Maybe 10-20 hours a year of use. Never any trouble nor any repair needed. No maintenance done on engine either. Just occasional airfilter cleaning and plug inspection and chain stuff.

Yesterday, used it for about 1 hour or so cutting down a big palm tree. All of that with the bar horizontal (saw on its side). A bit of trouble getting it started towards the end. Today worked for 1/2 hour again sideways, with progressively more trouble keeping it going. Now I can't get it started at all.

Current symptoms: if I try to start it, I'll set it to full choke, pull 3 or 4 times, it will very briefly (1/10 sec) catch on then stop. As it always did. At that point I'll set it to 1/2 choke, pull 3 or 4 times, it'll get going at high speed, as it always did. What's new is that now after a second or 2 or 3 it'll stop if I don't do anything to the throttle. If I do crank the throttle I may be able to nurse it for a few seconds and then it'll die. If I then try to start it with no choke it will simply not go, whereas before it would always go on first pull with no choke when hot.

Air filter is clean. Plug appears OK. No major goop, beige post (lighter on one side than other). Gap is set to specs. There is gas. Chain moves freely. Plug boot on firmly. I tried briefly minor changes to carb adjustments with no success and set it back more or less to original settings.

gotta finish that palm quick. Thoughts?

TIA

 

[Dave-T]

New plugs are never a bad thing. I've had ones that look nice go bad on me.

Be sure fuel delivery components are good. You've got mixed gas right? I've seen straight gas put into 2-cycle engines, not good. Other than that sounds like maybe you developed an air leak somewhere.

 

[D'Animal]

You have a restriction in you fuel system. Have you checked the fuel filter? it comes apart once you take it out of the tank.

Since the saw is as old as it is, you may have a crack in the fuel line or the impulse line. One end of the fuel line is hooked to the fuel filter and the oter end is connected to the carburetor. It has a molded in grommet where it comes through the fuel tank. Above that grommet you will probably find a crack.

The impulse line connects to a nipple on the back of the carburetor housing and to the bottom of the cylinder. You can use a flashlight and look between your black handle bar and your side cover down into that cavity. If you cannot see anything you can use compressed air and blow out the nasty stuff. If you still cannot see anything you need to remove the 4 screw that hold the start assy on. If you look behind the ignition module you will see the hose clearly. Check for cracks. Which ever one is cracked the other is not far behind.

 

[e9999]

thanks, will look first at filter. Yup, sounds like a fuel restriction. Must have sucked some nasty stuff up the line.

 

[e9999]

right on!

you guys called it just fine. Fuel line from tank to carb shows several small cracks. Probably pulling air in.

Now to find the part!


Man, ain't MUD great! Well, or more to the point aren't MUDders great!


thanks!


oh, and that was in less than 1 hr too.... super!