Stihl Ms261C Issues

[prodigey]

I have an early version of the Stihl Ms261 which is the M tronis version. It will start run and idle just fine but instantly dies when throttle is pressed all the way. Have replaced solenoid, vent cap, gas lines, gas filter and still doing it. Also have done the reset multiple times...any help is greatly appreciated

 

[SawdustKing]

If your engine quits when you're going full speed, first see if the air filter or muffler is blocked. Check the throttle position sensor and its wires, too. M-Tronic needs good signals to work right, so a bad sensor or a loose wire can make it cut out when you're working hard.

 

[prodigey]

ive taken muffler off and re installed it no blockages than i can see... im starting to think its a wiring short. i ordered a new wire from the stator to kill switch hopignt hats it..where exactly is a throttle position sensor? in the handle?

 

[STIHLTECH]

There is a screen inside the carburetor. Must be clean. Other that the solenoid and no adjustment screws, it is like any other 2 stroke saw. Diaphragms must be soft and not stretched.
Also check the pulse hose. No good pulse, no good fuel to carb, especially under load and high speed.

 

[JJoe_257]

ive taken muffler off and re installed it no blockages than i can see... im starting to think its a wiring short. i ordered a new wire from the stator to kill switch hopignt hats it..where exactly is a throttle position sensor? in the handle?

It sounds like you've already ruled out most of the obvious stuff and replaced many other parts..
I'd also think a wiring issue is definitely a possibility.
If you've replaced the solenoid and lines, and checked the muffler, it really points back to something with the carb or the wiring to it.
It's a closed-loop system, so it could be a sensor reading or a bad connection.
If the new wire doesn't fix it, you might be looking at a bad carb, which would be a real bummer, but not unheard of with those early M-Tronic models.
Hope the new wire sorts it out for you!