MS261CM M-Tronic Issues and Many GFY’s

[RI Chevy]

Buncha hostile pricks in this thread.

All because the smell of the oil. WTF
Go figure.

 

[RI Chevy]

Anyone ever do shots of red armor ? .. it tastes like after shock.

Try it and let us know Ryan. Helps with constipation too I bet.

 

[dall]

Try it and let us know Ryan. Helps with constioation too I bet.

let us guess you have the opposite problem lol

 

[RI Chevy]

No sir. You must be on your 3rd pack of smokes and 3rd pot of coffee by now, No???
You young whippersnapper you

 

[dall]

No sir. You must be on your 3rd pack of smokes and 3rd pit of coffee by now, No???
You young whippersnapper you

pit ?
and i only smoke a pack a day not 3 gramps

 

[maulhead]

No sir. You must be on your 3rd pack of smokes and 3rd pit of coffee by now, No???
You young whippersnapper you

Pot?

 

[tree monkey]

poke...……..…...poke...…………………. poke poke poke

 

[ChipsFlyin]

You guys are focken funny!

 

[sawmikaze]

Try it and let us know Ryan. Helps with constipation too I bet.

I did try it..that's how I know what it tastes like.

 

[RI Chevy]

Yikes. Well. Would ya do it again??? [emoji15]

 

[sawmikaze]

Yikes. Well. Would ya do it again??? [emoji15]

I'll do anything twice.

 

[RI Chevy]

OK good. If I see you at a gtg we'll do a shot of it together.

 

[sawmikaze]

OK good. If I see you at a gtg we'll do a shot of it together.

I drink pennzoil and valvoline too.

 

[Redfin]

I'll do anything twice.

Teddy BigT to the Moronic thread. Paging BigTdouble, please come to the thread.

 

[drf256]

Colder plug?

I believe a plugs heat rating refers to how hot the electrode gets for its own self cleaning, not for how much heat it puts into the combustion chamber. The reach of a plug isn’t the same as it’s heat rating. A cooler plug may result in a plug that fouls quicker IMHO.

I guess if the plug is really glowing cherry red or their is preignition I could understand it. I don’t believe their was any detonation in this saw.

Squish area doesn’t ignite, so that amount is lost for power output. The tight squish results in more swirl and better combustion of the chamber content. Increasing squish in this saw reduced static compression a bit. I like 15-18 in a 50cc saw. This saw didn’t like it. If the chamber was larger, the squish of 15 likely woulda been fine.

All compression does is add energy to the charge so that it’s pre-excited and will burn better/faster. Energy is never lost or gained, it just changes form. Too much compression and the saw will lose power making compression over the gain in combustion efficiency. Kinetic ====>Potential====>Kinetic Energy.

 

[ChipsFlyin]

Colder plug?

I believe a plugs heat rating refers to how hot the electrode gets for its own self cleaning, not for how much heat it puts into the combustion chamber. The reach of a plug isn’t the same as it’s heat rating. A cooler plug may result in a plug that fouls quicker IMHO.

I guess if the plug is really glowing cherry red or their is preignition I could understand it. I don’t believe their was any detonation in this saw.

Squish area doesn’t ignite, so that amount is lost for power output. The tight squish results in more swirl and better combustion of the chamber content. Increasing squish in this saw reduced static compression a bit. I like 15-18 in a 50cc saw. This saw didn’t like it. If the chamber was larger, the squish of 15 likely woulda been fine.

All compression does is add energy to the charge so that it’s pre-excited and will burn better/faster. Energy is never lost or gained, it just changes form. Too much compression and the saw will lose power making compression over the gain in combustion efficiency. Kinetic ====>Potential====>Kinetic Energy.

I'm learning. Increased compression>better faster burn>more heat? I saw heat as the potential problem and tried to figure out what the MT would read. What if the compression ,timing and ignition is all working fine? Is the MT is truly measuring heat where is that measurement coming from? Is it the plug? I'm assuming it would be in electrical changes with the heat giving feedback to the MT. Changes in electrical resistance? Is the regular plug getting too hot not releasing enough heat and not firing efficiently. Not preignition just not efficient. That my thinking with a cooler plug. I don't know. Just running through goofy scenarios.

 

[DND 9000]

No, no the system is not so complicated and smart as you think. As I`ve already said on the 1st page of this thread.

The m-tronic control units have a temp sensor in it, to get the "engine temp".

No spark plug resitance measurement or something like that.

 

[ChipsFlyin]

I need to read better. I miss stuff when looking on my phone - impatient and scroll too fast. I'll close my trap and pay better attention.

 

[Marshy]

Having MT issues with a 261 I just finished. This is the second one I’ve done that has had a problem.

The saw:
MS261CM manufactured 11/18
30 out of chamber
45 off base
Squish true .015
Timing advanced 1/4” of travel at Flywheel perimeter
Muff Modded
Extension trimmed and semicircle cutouts relieved.
Didn’t touch piston or stratos.

Ran factory reset on the MT 3 times.

Running pump gas with Motul800 at 32:1.

Issue:
I’m running a 25” 3/8 full comp, which is entirely too big for the saw. I wanted to see the difference full porting would make vs. just a TA/MM. Without nice square wood I figured a bar this big would make or break the question of what performed better.

Maybe this much load is just too much for the lil’ guy, but I don’t think a saw should heat up and do odd shít. Maybe I’m asking too much from it and it’s telling me GFY Al.

Runs fine till it’s loaded up good, then odd stuff occurs. Loses power in the cut, then sputters, then sounds lean. After a bit of time, saw comes back to normal.

Pulled carb after issue, popoff pressure >35psi. I couldn’t even get it to pop at max Mitivac pressure. Lowered popoff to around 35psi. Got same deal.

My thoughts:

1- Fail Safe? Saw gets too hot and MT says Uncle?
2-Vac leak? Haven’t checked yet, but will. MT can compensate until saw gets hot, then GFY.
3-More Power needs more fuel, and popoff too high. Running out of fuel in cut, gets hot, MT can no longer adjust. Does Weird Shít again.
4-32:1? Too viscous a mix to flow enough for the MT?

Saw seems to make no power suddenly. Happens like a light switch. Then a piss rev sounds way lean. Wait a few seconds, piss revs back to normal. Normal power again.

Fuel same as run in other saws without issue.

Sorry for long winded post. Wanted to be as descriptive as possible.

Thanks for the help.

Maybe retard the timing and see how it behaves. Just dont fo full retard.

Oops, 8 pages lol.

 

[drf256]

Maybe retard the timing and see how it behaves. Just dont fo full retard.

Oops, 8 pages lol.

I went full retard on this saw, then I had to back my way out.