MS 462 M-Tronic reset / data pull

[Jimmy in NC]

I have an 462c-m here that was brought to me for a top end. Customer [commercial tree crew] is very leary of M-tronic saws at this point as they have had several fail sooner than they expected. I told them I would pull a vac test and go through it top to bottom to ensure it is top notch when it leaves me.

When it arrived it passed a vac and pressure test with flying colors. I ordered all OEM parts to repair it and my local dealer has agreed to scan it / hard reset on it.
The saw is together at this point which included:

OEM top end
OEM gaskets
New Orange fuel pickup/filter
New white solenoid (same color that was in it)
Carb cleaned and new gaskets, needle, etc installed (passes a pressure test)
New plug

I have NOT started or even pulled the rope over more than a S-L-O-W pull. I do not want to generate any more "failed start" data than I am sure is already in there.

Now my dealer claims there is little data to be pulled from the saw's 'memory' but I think there is info there if you know how to read it. I would think if it had a fuel demand of 100% at time of failure, it would point to a fuel restriction. I'd love to see RPMs at failure (if available) to know how it was running when it cooked.

Cylinder was scored mainly exhaust side indicating a lean seize or VERY hot. Having never had the chance to see the fuel values or anything else am I expecting too much from a scan before starting? Looking for advice from those that have the software or those that have been into these more than me. I have minimal experience with any of the AutoTune / M-tronic saws.

Thoughts? Ideas?

 

[timg]

@Mastermind

 

[Jimmy in NC]

I guess it goes with out saying, saw is headed to the dealer for a scan, then a start/reset. I just want to be very clear what to look for specifically if anything before and after the reset. Anything to look for errors in my work?

I don't want to have taken money to rebuild a saw and have it quickly fail due to something I did not do. Tree crew.. anything is possible....

 

[Mastermind]

I guess it goes with out saying, saw is headed to the dealer for a scan, then a start/reset. I just want to be very clear what to look for specifically if anything before and after the reset. Anything to look for errors in my work?

I don't want to have taken money to rebuild a saw and have it quickly fail due to something I did not do. Tree crew.. anything is possible....

You're overthinking it.

 

[Jimmy in NC]

You're overthinking it.

Pull the cord and stick it in the wood?

 

[Mastermind]

Pull the cord and stick it in the wood?

If it makes it through the reset without stalling....run it.

 

[hacskaroly]

Cylinder was scored mainly exhaust side indicating a lean seize or VERY hot. Having never had the chance to see the fuel values or anything else am I expecting too much from a scan before starting? Looking for advice from those that have the software or those that have been into these more than me. I have minimal experience with any of the AutoTune / M-tronic saws.

I just worked on a low hour 261c run by a forest service crew, sounds the same as you describe, the saw is all OEM, maybe had two or three tanks of fuel through it (fresh fuel when I got it) and the exhaust side of the piston was all sorts of scorred with some transfer on the cylinder. The cylinder cleaned off fine and I put a new piston in it and let it idle through a tank of gas.

I explained to the crew that I assumed that they only use the saw when needed, maybe a daily start, gun it and then shut it off (all in less than 10 seconds) to make sure it works and when using it, fire it up, immediately bury it in wood and then shut it off when the cut is complete (no warm up or cool down). They stated that yes that is how they treat the saw. I explained the benefits of letting the saw warm up and cool down.

As in the case with your saw, if there is only damage on the exhaust side and the fuel is good without any air leaks, then my guess is that they are firing it up, burying it straight in the wood and the possibly shutting it down right after the cut. But that is just my guess from this side of the internet. I didn't have a way to access the computer side of the saw, so I had no idea of what it had, just the info from the crew. They were about to chuck the saw because they were quoted a new piston, cylinder and who knows what (labor too - past warranty). I was able to get them up and running with a Duke's coated piston for about $25. I also did a reset just before the tank ran dry and it performed as it should.

 

[huskihl]

Being a 462, they are all version 3 mtronic, so anyone can do the calibration. If the dealer runs the diagnostic tests on the carburetor, wire harness and coil you can get some information from that. At least you would know that they checked out good

 

[Jimmy in NC]

Thanks for the feedback. I'll let you know how first fire up goes.

 

[Jimmy in NC]

Saw started fine but shows on the leab side of normal on the MDG6 but still in tolerance. The brand new solenoid I installed fails the self test of leakage. Dealer is trying to get Stihl to warranty the part for me as it was clearly a faulty part.

Building a relationship with a dealer is huge ...