Jon1270
ArboristSite Operative
@blsnelling
A tree service that I get firewood from asked me to look at a 441C-M they've been having problems with. Their complaint was that it didn't have any power in the cut. They said they'd had the carb rebuilt by the dealer a couple of months ago.
This is my first M-Tronic project, so I'm still getting my bearings. I checked all the fundamentals -- I looked at the piston, checked compression, did pressure and vac tests on the motor and fuel line, and pressure-tested the carb to confirm the metering valve was sealing. All of that checked out fine. Metering lever is set flush with the carb body. Couldn't find any damaged wiring. Plug looks good. Fuel filter was dirty, so I replaced it, but I didn't find any obvious smoking guns.
After putting it back together I did the M-Tronic reset procedure and took it out for a test-run, noodling some large rounds of red maple. Its behavior is really erratic. Most of the time it hesitates a bit when accelerating from idle. Sometimes it bogs down under even the slightest load, but then it will get going and make all sorts of power and cut beautifully. If I set it down and let it idle for 30 seconds or so, it will die the moment I pick it up, as if fuel is puddling in the intake or crankcase. When this happens it will refuse to restart unless I hold the throttle open, which makes it easy.
I found a few old threads about similar 441 problems from the last couple of years, with suggestions to adjust the metering lever and fresh air butterfly set screw, replace the carb, replace the coil, buy a Husky... so, I've seen all of that. Since this combination of symptoms isn't a perfect match for what I saw discussed in other threads, I thought I'd post this and see if it rings any bells before I continue. TIA.
A tree service that I get firewood from asked me to look at a 441C-M they've been having problems with. Their complaint was that it didn't have any power in the cut. They said they'd had the carb rebuilt by the dealer a couple of months ago.
This is my first M-Tronic project, so I'm still getting my bearings. I checked all the fundamentals -- I looked at the piston, checked compression, did pressure and vac tests on the motor and fuel line, and pressure-tested the carb to confirm the metering valve was sealing. All of that checked out fine. Metering lever is set flush with the carb body. Couldn't find any damaged wiring. Plug looks good. Fuel filter was dirty, so I replaced it, but I didn't find any obvious smoking guns.
After putting it back together I did the M-Tronic reset procedure and took it out for a test-run, noodling some large rounds of red maple. Its behavior is really erratic. Most of the time it hesitates a bit when accelerating from idle. Sometimes it bogs down under even the slightest load, but then it will get going and make all sorts of power and cut beautifully. If I set it down and let it idle for 30 seconds or so, it will die the moment I pick it up, as if fuel is puddling in the intake or crankcase. When this happens it will refuse to restart unless I hold the throttle open, which makes it easy.
I found a few old threads about similar 441 problems from the last couple of years, with suggestions to adjust the metering lever and fresh air butterfly set screw, replace the carb, replace the coil, buy a Husky... so, I've seen all of that. Since this combination of symptoms isn't a perfect match for what I saw discussed in other threads, I thought I'd post this and see if it rings any bells before I continue. TIA.
