STIHL M-Tronic™ engine management system

jargo432 · April 04, 2014, 10:53:55 PM

Has anyone had any problems with the STIHL M-Tronic™ engine management system.

Andyshine77 · April 05, 2014, 12:59:38 AM

Quote from: jargo432 on April 04, 2014, 10:53:55 PM
Has anyone had any problems with the STIHL M-Tronic™ engine management system.

Very very few issue. The two I know of were on ported saws, and a simple adjustment resolved the problem.

sablatnic · April 05, 2014, 02:05:36 AM

I have had three to give problems, one fuelled with water, one with chain oil, and one with diesel. After a cleaning they all three ran again without problems!

missedbass · April 05, 2014, 04:35:44 AM

If the old school 261 has limiter caps on the carb adjustment screws that some members remove to richen it up, how does the m-tronic come set from the factory? Is it programmed to be set on the lean side and how can you make adjustments?

Reddog · April 05, 2014, 09:06:20 AM

Quote from: jargo432 on April 04, 2014, 10:53:55 PM
Has anyone had any problems with the STIHL M-Tronic™ engine management system.

Was just talking to my dealer about this the other day.
He said he couldn't remember the last time one needed a fix or adjustment for a problem. They are quite impressed with the M-Tronic.

missedbass, the same way any open loop fuel throttle body system works.
The throttle position sensor (TPS), tells the computer chip what rpm you want. The computer then uses the crank sensor to adjust the mixture to match that rpm.
Not sure how many other inputs the mtronic uses in its micro processor.

missedbass · April 05, 2014, 10:12:50 AM

Thanks, was just wondering if the saw could run too lean with the m-tronic

Reddog · April 05, 2014, 11:00:45 AM

The consensus from saw builders so far seems to be no. They can adjust to run a ported saw rich enough.

No personal experience though, so YMMV.

Andyshine77 · April 05, 2014, 12:17:14 PM

Quote from: Reddog on April 05, 2014, 09:06:20 AM
Quote from: jargo432 on April 04, 2014, 10:53:55 PM
Has anyone had any problems with the STIHL M-Tronic™ engine management system.

Was just talking to my dealer about this the other day.
He said he couldn't remember the last time one needed a fix or adjustment for a problem. They are quite impressed with the M-Tronic.

missedbass, the same way any open loop fuel throttle body system works.
The throttle position sensor (TPS), tells the computer chip what rpm you want. The computer then uses the crank sensor to adjust the mixture to match that rpm.
Not sure how many other inputs the mtronic uses in its micro processor.

No TPS sensor on the Stihl Mtronic saws. It's a simple feedback system that looks for max rpm under load. Too lean you loose rpm, too rich you lose rpm. The Husky's have a TPS sensor. Most if not all the issues Husky has had are carb problems, not AT issues.