It's here! The M-Tronic MS261C is finally here.

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blsnelling said:
It handles the significant gains the Stage 1 mods gave it. Those gains are very real. It just can't handle the radical mod of gutting the strato. It could probably handle some more traditional porting. However, I didn't find the gains I wanted with traditional porting. I'll try to find those vids.
Click to expand...

Question Brad, when you were looking for the gains in your original 261 development, did you have your lathe to mill the cylinder? If not, just wondering if the M-Tronic plus higher compression could breathe more life outta' porting without the full de-strato mod.
 
john_bud said:
I also wonder if there is a software issue with the fueling of the full ported saw. I don't know squat about how the saw senses and corrects for variations and tunes itself. but it seems reasonable that could be the issue. Are we at the stage when chainsaw hot rodders need to do a mind meld with computer nerds??:laugh:
Click to expand...
The limiters need to be removed!! But now they're digital...
 
Officer's Match said:
Question Brad, when you were looking for the gains in your original 261 development, did you have your lathe to mill the cylinder? If not, just wondering if the M-Tronic plus higher compression could breathe more life outta' porting without the full de-strato mod.
Click to expand...

I made the same compression increase, but had to either ditch the gasket or make a thin one. I don't recall which. The net effect was the same. I've tried higher compression in a 261, and actually slowed it down. 180-190 PSI is all the compression needed for a strong work saw.
 
wonder how the carb acts when it's really cold and needs a good amount of fuel in winter time with the stage 1? do you think it has enough headroom to compensate after they've been opened up but not ported? thats a huge question for me cause a MM is first thing done to a saw and it usually takes a 1/4 turn out on the high screws to tune them right afterwards. i would have been nice for stihl to put some headroom there just in case. seems they have picked a very narrow operating band for the jet...wonder how we can change that :confused:
 
hoeyrd2110 said:
wonder how the carb acts when it's really cold and needs a good amount of fuel in winter time with the stage 1? do you think it has enough headroom to compensate after they've been opened up but not ported? thats a huge question for me cause a MM is first thing done to a saw and it usually takes a 1/4 turn out on the high screws to tune them right afterwards. i would have been nice for stihl to put some headroom there just in case. seems they have picked a very narrow operating band for the jet...wonder how we can change that :confused:
Click to expand...

A fully modded MS261 feels more like a 70cc saw than a 50cc saw. Honestly, I'm not surprised at all that it didn't work out. I wasn't asking it for just a little head room. Gutting the strato on this thing is a rather radical change from the factory design. Obviously, I can't say for sure, but I'd be surprised if it wasn't fine in cold weather. As far as MMs go, I've seen saws need the H leaned out. Typically, you need a lot more L, which adds to WOT fuel. Every saw is an individual though.
 
we should all call hillborn and get this injection thing figured out hehe. adjustable barrel valve and a crank driven mini pump should give you all fuel you need:hmm3grin2orange:
 
This video demonstrates why I won't offer traditional porting on a 261. The difference is HUGE. The first cut is with traditional porting, the second is with the strato gutted. I'm able to put a lot more load on the saw, netting a 20% reduction in cut times.

[video=youtube_share;TLJVAR6GmkE]http://youtu.be/TLJVAR6GmkE[/video]

I hope that anyone that tries traditional porting on a 261C will demonstrate the gains it makes over what I'm calling Stage 1 mods. If not, there's no proof what the porting did. We already know that there's approximately 40% gains to be had without porting.
 
Going back and studying my initial 261 build, it appears that I got more than twice the gains with gutting the strato than I did with traditional porting. If I'm looking at the right vids, traditional porting was only good for about 12%.

Traditional porting.
[video=youtube_share;28mfeVlj_og]http://youtu.be/28mfeVlj_og[/video]
 
Alright, alright. Back to the 261cm.

So are we, Brad, looking at ways to get more fuel or just saying it cannot be done?

It sounds like a bit more R&D needs to be done on this saw.

The other day I was at the dealer and he showed me the tool that is used to hook up the M-tronic saws to the computer for diagnosis. I forget the part number. The main part plugs into the saw and then there is a Bluetooth dongle that plugs into the desktop computer and transmits all the programming data to the PC wirelessly. The tool can also check coils and possibly does a few other things. I am not sure what parameters you can adjust, if any, but it might be a step in the right direction. There has to be a way of hacking into the M-tronic system and adjusting anything we want. Well maybe not the chain tension.
 
LowVolt said:
Alright, alright. Back to the 261cm.

So are we, Brad, looking at ways to get more fuel or just saying it cannot be done?

It sounds like a bit more R&D needs to be done on this saw.

The other day I was at the dealer and he showed me the tool that is used to hook up the M-tronic saws to the computer for diagnosis. I forget the part number. The main part plugs into the saw and then there is a Bluetooth dongle that plugs into the desktop computer and transmits all the programming data to the PC wirelessly. The tool can also check coils and possibly does a few other things. I am not sure what parameters you can adjust, if any, but it might be a step in the right direction. There has to be a way of hacking into the M-tronic system and adjusting anything we want. Well maybe not the chain tension.
Click to expand...



^ not yet on the chain tension, but it should be possible with a built in strain gauge and a mini stepper motor...:laugh:
 
LowVolt said:
Alright, alright. Back to the 261cm.

So are we, Brad, looking at ways to get more fuel or just saying it cannot be done?

It sounds like a bit more R&D needs to be done on this saw.

The other day I was at the dealer and he showed me the tool that is used to hook up the M-tronic saws to the computer for diagnosis. I forget the part number. The main part plugs into the saw and then there is a Bluetooth dongle that plugs into the desktop computer and transmits all the programming data to the PC wirelessly. The tool can also check coils and possibly does a few other things. I am not sure what parameters you can adjust, if any, but it might be a step in the right direction. There has to be a way of hacking into the M-tronic system and adjusting anything we want. Well maybe not the chain tension.
Click to expand...
I have every confidence that the Mtronic will be modded/hacked/etc sooner than later.
 
LowVolt said:
Alright, alright. Back to the 261cm.

So are we, Brad, looking at ways to get more fuel or just saying it cannot be done?

It sounds like a bit more R&D needs to be done on this saw.

The other day I was at the dealer and he showed me the tool that is used to hook up the M-tronic saws to the computer for diagnosis. I forget the part number. The main part plugs into the saw and then there is a Bluetooth dongle that plugs into the desktop computer and transmits all the programming data to the PC wirelessly. The tool can also check coils and possibly does a few other things. I am not sure what parameters you can adjust, if any, but it might be a step in the right direction. There has to be a way of hacking into the M-tronic system and adjusting anything we want. Well maybe not the chain tension.
Click to expand...

john_bud said:
^ not yet on the chain tension, but it should be possible with a built in strain gauge and a mini stepper motor...:laugh:
Click to expand...

I wouldn't hold my breath. I don't think the aftermarket chainsaw world has the R&D dollars to replicate the data interface and software that would be required. Similar hardware and software for my truck cost in the ballpark of $1000 just to purchase. There just isn't that kind of market for what we're doing.
 

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