Brand new ms661 bog (Mtronic 3.0)


Well-Known Member
Is it still under warranty?
Just to be clear, it runs great after warmed up, but warm up takes a long time?
100% still under warranty. However, calibrating Mtronic seemed to clear things up. I put a tank through it and it is 100%. Could have been confounding factors that contributed: old-ish fuel and not letting it warm up for a couple of minutes.

Barc Buster

Well-Known Member
I like the second sequence on the newest models....seems a lot more likely to calibrate correctly and also the RPM changes allows you to be certain that the function is indeed working.
Me too. It's important to remember that each sequence is version specific though.


Well-Known Member
An update...

This thing became a different saw after about 10 tanks. Holy crap. I can lean on it now. Still takes a while to warm up, but once it does...dag. it's scary


I was having carb issues with my 661 seemed like the air filter was not making a good deal to the houseing.
Solution: take some grease and goop up around the air filter where it seats against carb body. Apply liberally. It will help create a deal against dust & shit getting through the gap. No more carb problems since. I am doing g it on all my stihls now and have been really pleased. The carbs are so sensitive it's worth a try


Well-Known Member
And also, do y'all mix a few gallons at a time, or what?
I have 5 gal and a 2.5 gal all mixed 50:1 with Stabil fuel stabilizer. Someone mentioned using the site. Do it. Find a dealer that sells 93 non-E, mix it with the Stihl ultra synthetic oil and dont look back.

As far as the saw bogging, almost every saw I own does that right off a cold crank, including my mtronics - 241 v2, 362 v3, 661 v2. The best saw is a 271 which takes almost no time to start ripping. It also my oldest saw.