Ms261 lean condition

[jurchybald]

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Or add duration to the mix intake.
now it's 83/84
What makes you feel it’s running lean?

not a single burble in a cut, hessitation off throttle, by now probably drama in my head

 

[drf256]

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What makes you feel it’s running lean?

I started thinking the same thing.

At least with the MT models, they run on the edge of lean. The exhaust sides of the pistons look completely different than non strato saws. At least in mine, there isn’t any oil sheen and the skirts look dry and coked a bit. Sometimes get weird patterns on them, along like oxidation one sees when a saw sits non running for years. It’s a result of the stratos actually working and not getting a bunch of unburned mix leaving the saw cylinder.

 

[Moparmyway]

I have put bigger jet in mtronic yesterday.

I did that by changing main jet.

Do you have pictures of the 2 jets ?
What size was in there ?
What size did you put in there ?

 

[jurchybald]

I do not have picture of jets because stihl rep changed it for me. I don't have a press. But he told me he put one from 346xp zama. He's probably reading this and can freely engage in conversation.

 

[Moparmyway]

I don't want to get into any "this or that" ,...............

You have asked and some very experienced guys have answered.
Do with it what you will, but nobody here said to replace the jet, everyone here said to drill it out carefully

Why do you think that is ?

 

[Woodpecker]

I do not have picture of jets because stihl rep changed it for me. I don't have a press. But he told me he put one from 346xp zama. He's probably reading this and can freely engage in conversation.

Lol No press needed. Shoot do you think every hvac tech brings a drill press with them on their service vehicle just to use their micro bits to rejet a furnace? All you need is a set of bits and a pin vise. Maybe 20 bucks for a Chineseium set which is all you’d ever need.

 

[jurchybald]

All good! Ive been around this forum for years and belive me when I say I respect opinions from any of you. Thing is I don't have drills nor knowledge to do it and only option was to change it.

Im gonna run the ported mtronic little more and than go inside again just to be sure before final decision.

Thanx to all

 

[huskihl]

All good! Ive been around this forum for years and belive me when I say I respect opinions from any of you. Thing is I don't have drills nor knowledge to do it and only option was to change it.

Im gonna run the ported mtronic little more and than go inside again just to be sure before final decision.

Thanx to all

Just so you know, that main nozzle is the only limiting factor on the amount of fuel the motor receives, as long as the mtron is working properly. It may work perfectly, I don’t know. Just saying that if it’s a smaller hole than what was in the carburetor originally, things will go south pretty quick.

 

[Wonkydonkey]

I read the ms 461 modding by Randy & brought those micro drills off eBay and drilled the main jet just a bit smaller than he said, and it worked …

me thinks other’s advice is better than that person (the stihl rep) .

 

[drf256]

The jet is in the main nozzle.

You tap the nozzle into the bore with a flat punch. Drill it one micro size bigger and tap it back in to same position which I believe is flush to the metering chamber. There is a single hole halfway up the nozzle body. That is what you will be drilling.

I think we drilled them to .8mm. Just go up one microdrill size. We figured out that the newer 261CM models already got drilled bigger from the factory.

Again, only matters if ported.

 

[jurchybald]

Thanx for drilling advice. I will order bits and check it out.

 

[jurchybald]

I want to sum this thread. After several tanks saw is running perfect. Patterns on the jug are exactly the same as they were after 2min of run time. Mr. Huskihl was right it doesn't get any worse.
And stock jet is okay. M troni V3 needs time to adjust. In my experience 2-3 tanks.first it appears to be running lean. There is absolutly no burble in the cut

 

[jurchybald]

After few tanks it starts to burble like any other saw.

So thanx again and happy new year!