Husky 445 dies after warmup=frustration! Updated, running great

[gibby2235]

Hello all, been searching for an answer, I have seen a number of possible solutions, just not much feedback afterwards to know what worked for others. Anyway, have a 2010 husqvarna 445. This saw probably has 4-5 hours run time on it, total. Starts easily, runs great for a cut or two, then bogs and dies. Won't restart until it completely cools, then same thing again. Getting good spark, even after it dies. Visual inspection of fuel lines look good. Just today I tried opening up the muffler a bit, drilled 3 3/16 holes and backed off the H screw about a 1/4 turn. No improvement. Have tried opening gas cap, nothing. Fuel is supposed to be ethenol free, don't know if I trust the place, but my old tractor hasn't had any problems lately and it REALLY doesn't like ethenol. Plus I use stabil in the gas w/mix. Gas is less than a month old. I haven't cleaned or rebuilt carb, guess that's on the to-do list. It just doesn't make much sense to me that it would run fine until hot if it were carb. I've tried running it without plastic top cover to see if it would run cooler, nope. I'm really frustrated with it! Any thoughts on what I should be looking for? I have a coworker with the same saw, and his does exact same thing, he just broke down and got a stihl, but I don't want to spend the coin! Any help would be MOST appreciated!

 

[pioneerguy600]

Take the muffler off and check the piston and rings. Is the cylinder getting overheated. Running a saw with the engine cover off will severely overheat it, the air from the flywheel needs the cover on to redirect it around the cylinder.

 

[CrufflerJJ]

Have you checked compression when the saw is cold, and also when it's hot?

Changing the spark plug would be a cheap thing to try.

 

[AVB]

uel is supposed to be ethenol free, don't know if I trust the place, but my old tractor hasn't had any problems lately and it REALLY doesn't like ethenol. Plus I use stabil in the gas w/mix. Gas is less than a month old.

Testing for ethanol is very easy if you have 125 or 250 ml test container. Mark the container at either 25 or 50ml from the bottom depending on the container. Add 25 or 50 ml of water then 100 or 200 ml to the container (you multiples of 100 for easy readings). Now shake for a little bit to mix and sit aside to settle. The ethanol and water will combine and settle to the bottom any amount over the added water is your ethanol content. Using the 100ml amount of fuel and you ended up with 90ml after separation then you ethanol content would be 10%.

If a new plug doesn't fix I would think the electronics in the coil are shifting the timing so much that it no longer fires at the correct time and needs replacing.

 

[gibby2235]

Thanks for the responses. I did pull muffler, piston and rings look good. Obviously didn't think of that on the cover, won't do that again! I did only try it once, hopefully not enough to damage.

I haven't tested compression, don't have a tester, although as often as I'm working on something it would come in handy. Spark plug looks good, and has good spark, but if the timing was off, that wouldn't matter. I will change the plug and go from there.

 

[gibby2235]

So when I said it looked to have a good spark, I should have mentioned that it was one of those E3 plugs...lesson learned. Swapped back to ngk and started cutting away.
It did appear to have a strong spark, at least out of the cylinder.
Many thanks for the assist!