Stihl MS261 C-M 3/8 Chain?

[KG441c]

The clutch cover will require longer bolts but the stock casing bolts work

 

[windthrown]

I had a heap of 026/260 saws once and they came with a mix of .325 and 3/8 B&C. I was using both but is was a pain to sharpen different loop sizes and I preferred running 3/8 standard chain. I did a bunch of tests cutting fir cookies with full chisel 16 and 18 inch bars in both .325 and 3/8, and for my cutting it was a dead heat. Same kerf, same cutting time. I ran all my larger saws at that time with 3/8 (still do), so I sold off all the .325 B&C and have been running 3/8 on my 026/260 saws ever since. It made my life simpler. Well... except I have a one large mount Picco bar and I run on one 026 with low profile for faster cutting. Picco runs really good/fast on an 026. They are selling 261 saws in Germany with that same Picco setup now. I run Picco on my 211 saw as well. I had a mix of .325 and Picco-3/8LP on my 025/250 saws before I swapped them out for 026/260 saws, and I flipped them all to Picco for faster cutting.

Its all 3/8 for me...

 

[fishinfiend]

I picked my 261 up earlier this week with an 18" 3/8 b/c. Yesterday I took it out to the woods and boy it seemed to have no power at all. It seemed to me that when it was in a cut that the saw would stall if I let the saw do the work. In other words I has to hold back the saw in order for it not to get stopped. Is that normal until I get through the break in period?

 

[moody]

That's not normal for a 261. Are you heavy handed?

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[fishinfiend]

I don't think I am, it just seems that the saw pulls itself into a too big of a cut.

 

[XSKIER]

... no one will ever agree on which drive pitch is best for the MS 261 C-M, so you might as well try .404 and let the rest of us know.

http://www.arboristsite.com/community/index.php?threads/238484/

I picked my 261 up earlier this week with an 18" 3/8 b/c. Yesterday I took it out to the woods and boy it seemed to have no power at all. It seemed to me that when it was in a cut that the saw would stall if I let the saw do the work. In other words I has to hold back the saw in order for it not to get stopped. Is that normal until I get through the break in period?

Did you get the narrow kerf .050 3/8 chain? You might try a loop of .404 .063 fool chisel. It sure cuts nice on my 42 cc 08, and, it is way easier to sharpen than .325 .063 that the MS 261 C-M should have came with.

 

[fishinfiend]

Yes I am running 050 3/8 chain. No I am not planing on changing my bar and chain anytime soon unless if I wreck it. I was thinking about shoving the bar into the ground and dulling it up a little bit.

Just kidding about saw in dirt.

 

[sunfish]

Ski dude has lost it, gone off the deep in!

Give the saw some time to break in, it'll get stronger.

...

 

[Philip Wheelock]

I picked my 261 up earlier this week with an 18" 3/8 b/c. Yesterday I took it out to the woods and boy it seemed to have no power at all...

Several things that might explain this: 1. New saws will often go through 5-8 gals of fuel mix before making full power; 2. Dealer tuned the saw a few hundred rpm below specs on the high end for break-in purposes; 3. 18" b/c w/.375" pitch buried might be a bit much for any new stock 50cc saw; a ported 261 is a different animal altogether.

 

[DonnerParty]

I picked my 261 up earlier this week with an 18" 3/8 b/c. Yesterday I took it out to the woods and boy it seemed to have no power at all. It seemed to me that when it was in a cut that the saw would stall if I let the saw do the work. In other words I has to hold back the saw in order for it not to get stopped. Is that normal until I get through the break in period?

My 261 C-M picked up a lot after the first few tanks. I am running 18" .325 .063 and the saw has plenty of power. It really rips.

Run a few tanks through it. If you are still having an issue, take it back to the dealer and have them look it over.

 

[mopar3]

If the saw is tuned too lean it will lack torque. They come set really lean from the factory. If your dealer did not retune for your weather altitude ect at set up your saw could be weak.


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[KG441c]

What is topend rpm that everyone likes to set at vs max rpm?

 

[Philip Wheelock]

What is topend rpm that everyone likes to set at vs max rpm?

Dealer tuned my MS261 to 13,750 rpm for break-in (vs. 14,000 rpm max. specified)

 

[mopar3]

Fishfiend did you get a 261 cm with m tronic or just a regular 261 with the standard carb?


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[fishinfiend]

I have it with the m-tronic and I now have about a tank and a half through it and it seems already like a completely different saw than when I just tried it out yesterday.

 

[fishinfiend]

Here is picture of the saw.

 

[windthrown]

I have it with the m-tronic and I now have about a tank and a half through it and it seems already like a completely different saw than when I just tried it out yesterday.

Several things about what some others have posted here... one, there is no 3/8 std. narrow kerf from Stihl. There is 3/8 LP/Picco narrow kerf, but that stuff is so small it only comes on the 170/171 and 180/181 saws. Stihl does not sell large mount saws in the US with 3/8 LP/Picco B&C. They sold that for a few months on some 024 saws many years ago, but stopped. Supposedly the 16 inch large mount Picco bar is available by ordering through east coast Stihl dealers, but... I have yet to hear anyone actually order one through them and get it. You can get that setup in the EU though. Stihl does not make a .325 NK bars or loops either, but some others do (like Cannon/Carlton). I do not know what these guys are talking about .404 on a 261 for... that is for large saws like the 660 and 880.

Another thing is that when saws are new they do not have full power. It takes about 10 tanks of gas to seat the rings in and gain full compression and thus full power. You do not need to throttle back on the saw to break it in. Just avoid running WOT out of the wood. Also with an M-tronic saw, the computer takes some time running to get the saw dialed in right. Once that happens, cutting should improve (as you seem to have found out). The computer chip will store the data from the last cutting session in memory so it does not have to re-calibrate the next time you use the saw.

The 261 has quite a bit more rated power than a 026, so you should have no problem pulling an 18 inch 3/8 standard B&C. Also the chain type will make a difference. If you are running factory safety (green) chain that typically comes from the dealer on saws, they are slower than non-safety (yellow) chain. Add to that semi-chisel will cut about 10% slower than full chisel, and a lot of dealers sell new saws with semi-chisel safety chain on them. Factory Stihl chains should be razor sharp, so the chain being dull should not be an issue unless you rocked it. If you do not have it, get a loop made of RSC non-safety full chisel Stihl chain, and use it for cutting in clean wood. Full chisel will cut faster, but also dull a lot faster in crud. Use semi-chisel loops for cutting in crud and out in the woods, as it will stay sharp a lot longer. Run the safety loops where you may rock a chain, or if there may be nails in the wood (like cutting yard trees).

 

[Stihlman441]

This is well known that the standard carb 261s like to run a little fat 13700 13800 rpm.

 

[fishinfiend]

Thanks for the info windthrow. I believe I have a rsk on the saw and another in the box cause my slip says that the extra chain is an rsk and I told my dealer that I wanted both non safety yellow chains. Also I was kidding about the shoving the saw into the dirt cause I don't want to sharpen the saw any sooner than I have to.

 

[windthrown]

This is well known that the standard carb 261s like to run a little fat 13700 13800 rpm.

Most newer standard carb Stihl saws do, but you have to pull the limiter tabs to fatten them up. Generally the maxed out EPA setting is about 1/8 a turn too lean. On an M-tronic saw there is no carb adjustment though. No little orange screwdriver needed.