As the tread title states.... past few times I have operate the big saw, it runs great until I am really getting after it, then it dies. Sometimes it starts, other times it must be stone cold. thoughts. It’s about three years old.
How long till it dies? Kinda sounds like a tank vent gone south. Have you tried opening the fuel cap after it dies and then trying to run it?
M2theB It will run fifteen minutes or so. Removing the cap doesn’t seem to help. Today I checked the fuel and topped it off. I will check the other ideas.
I think i understand. What I’m suggesting is run it until it happens again and when it does, remove the cap right then. And then try to run it. If that’s what you did and it still didn’t run, I agree, it’s on to the next thing.
I'd check all the fuel lines. I recently found the line that returns the fuel to the tank from the purge bulb had rotted out at the grommet, and it caused irregular behavior until it failed completely and wouldn't start. Those little hoses, if not perfect, can ruin how your saw runs. Good news is, they are cheap to replace, if not exactly easy (at least the first time).
One of mine was acting like that recently. It was a clogged fuel pickup filter. It absolutely didn't look clogged, it looked perfect but was the problem none the less. Sounds like you're losing spark or fuel. Test it by letting it run until it starts to die then shoot a quick shot of starting fluid into the air intake. If that keeps it running a bit then you have spark but no fuel.
Using starting fluid is like straight gassing it, no oil in the starting fluid and its very solvent to the oil in the cylinder, you can burn it up. My first thought was also the fuel tank vent, they only last so long, or the fuel line itself getting soft which is common. Fifteen minutes for that to happen is kind of a long time and makes me think you are loosing spark as things heat up which can be a more complex problem. Fuel lines and tank vent are much more common and an easier place to start. I would rule them out first.
You are correct. I was thinking about how I’ve tested 4 stroke engines. I will edit my post so that no one gets the idea that it’s ok to do that on a 2 stroke. Thanks! **it will not allow me to edit my original post**
This may be a long shot . But if it’s going 15 minutes before acting up , it may be something that takes time to heat soak like the coil .
