High RPM's on MS361

[West Texas]

I broke in a new MS361 last month for a non profit org that they will be using primarily on the 'fire line' fighting forest fires. And everything with it has gone according to the book; a fabulous saw. However, due to the break in process, I never ran it at max rpm in a cut, although its ready for that now.

Purpose of this query, is I've now bought a 'used' MS361 for my own personal use cutting firewood. I made the muffler mod of extra holes.

But, now I've got what may or may not be a problem, a sudden high accelleration in the cut. On two separate occasions, it sounded almost like it was running out of fuel, etc. but that is not the case, and it stops the higher accelleration when I push it down harder into the cut. As I said, this has happened on two different occasions; and, it may be that the dead oak wood is so hard that the full chisel chain is jumping up out of the cut and causing it to accellerate.

Current carb setting is 3/4 out on the H and 1/4 out on the L. Recommended settings. I have not removed the carb and blown it out or checked the lever setting. Which I can do; but, have not done as yet.

I don't know how high the rpms are supposed to be on the MS361, as I'm more accustomed to the 026/260 and 360/Pro sounds and performance. Based on what I've been reading on this site; it may just be a 'hotter' saw than I'm used to. But, I don't want to 'burn it up' either.

I don't have a tach; but, I can borrow one if necessary.

Am I over reacting or is there a concern here? Your Ideas and comments are welcome.

 

[SWE#Kipp]

if you open up the muffler you should give it more fuel or it will run to lean ,,

 

[12guns]

Search for "break in" on the site and you will be supprised...also don't set the carb to "recommended settings" they probably are not correct for your saw. all saws are different and need to be tuned professionally, or in the cut, in order to achieve max torque. I'm going out today to get my 026 cutting better. I'll probably end up richening up the mix a little as I've done a muffler mod and probably have been running it too fast to get more torque out of it

 

[Stihl Crazy]

A 361 should be set at 13,500 - 14,000 rpm. My 361's needed the carb stops removed and high speed jet set at 1 1/8 open to get this. With stops on they went to 15,500 rpm after breakin. Now the stops are removed from all news saws before they are ever started.

 

[West Texas]

Stihl Crazy, I knew you had a 361 'woods' saw and was looking forward to your comments. I've just been dragging my heals on pulling the carb; as I've been sorta snowed under with some roof work on my house. But I felt those stops and wished that I could have backed out more. Will be interesting to hear other comments too. Thanks

And 12 Guns that's usually how I tune the H jet too; but, I hit the limit stops before I got it where I wanted to go. No short cuts I guess. ha! Just gonna have to pull the carb and do it right I guess.

 

[West Texas]

Well I tore the carb apart and discovered a tiny piece of fiber or steel wire about a quarter of an inch long, lodged between the shaft of the needle and its rubber tip. Took a magnifying glass to see it well enough to remove it with tweezers. That could have kept the needle from seating properly and caused more fuel to enter the carb, than I was trying to do with the throttle. Its starts, runs and idles OK now; but, too dark to make a confirmation cut in a good log tonight.

 

[12guns]

The verdict is in...I messed w/ the high adj while in the cut of a huge, 35" dia...elm...i think. I richened the mix to an audible sputer, but still running fairly fast...didn't cut worth a crap. I leaned it out, and it cut much better. It seemed to hold rpms considerably higher. w/o the saw under load, I leaned it out further than I ever have before, sure runs smooth, but sounded much too fast so I brought it right back down. What I was worried about being too lean is not. My modded 026 will reach dangerously fast rmps, and run smooth as silk when not under load...when i readjusted back down a bit, i could then hear the "rougher" sound some of you have been refering to...I'll leave it alone for now.

 

[cbfarmall]

The verdict is in...I messed w/ the high adj while in the cut of a huge, 35" dia...elm...i think. I richened the mix to an audible sputer, but still running fairly fast...didn't cut worth a crap. I leaned it out, and it cut much better.

The idea is to tune it to blubber slightly OUT of the cut. That way, the engine will lean out under a load. If you had it blubbering under load, that was pretty rich.

Chris B.

 

[12guns]

The idea is to tune it to blubber slightly OUT of the cut. That way, the engine will lean out under a load. If you had it blubbering under load, that was pretty rich.

Chris B.

Sorry, that's not what i meant. It was not blubbering under load, but only out of load...seemed to cut the best more to the lean side, but w/ a little blubber out of the cut.