New MS361 stalls at idle sometimes?

[CNYCountry]

My new 361 is getting nicely broken in, more power in the cut. But I notice that after I run it hard for a while in decent sized wood and then set it down to idle for a few seconds sometimes it idles low then stalls. It's more prone to do it with the tank on the low side of 1/2 full, but it's far from empty. It will start but it takes several pulls. Normally if I shut it off and start it again warm it goes on one pull in low idle, just like a quality machine should.

Is this a vapor lock issue, carb setting or something else?

Or is this a normal thing?

 

[Kenskip1]

CNY,
I have a feeling that your problem may just be overheating.Being a new saw I will suspect that in this heat your mixture is set to rich on the low side. Just my humble opinion, Ken

 

[CNYCountry]

Exactly what I'm looking for, thank you!

Too rich is better than too lean, if I understand correctly, at least there is lubrication..

Hopefully I have not glazed the cylinder but the rings seem to be seating since the saw is growing a set of ****s now.

I've been thinking about taking it back to the dealer anyway and having them tweak the carb a little now that it's breaking in. I'd rather have them do it with a tach than me try it by ear...

 

[turnkey4099]

Exactly what I'm looking for, thank you!

Too rich is better than too lean, if I understand correctly, at least there is lubrication..

Hopefully I have not glazed the cylinder but the rings seem to be seating since the saw is growing a set of ****s now.

I've been thinking about taking it back to the dealer anyway and having them tweak the carb a little now that it's breaking in. I'd rather have them do it with a tach than me try it by ear...

Odd that I have had both problems, dieing on idle and running a lot better after two seasons on my ms310. Was out 2 days ago and really throwing a roostertail finally. Low idle - dealer today did some very minor carb adjust and increased idle speed a bit - same thing I was going to do.

Saw has eaten about 12 cord now and is finally up to (actually a bit better) than the Johnny red 625 I traded in. Traded that one as it was getting very long in the tooth and needing a carb kit among some other things.

Harry K

 

[fishhuntcutwood]

CNY- I think Kenskip is onto something. My 361 did that a few times, less than a half tank, but not near empty a while back. Then I had Dean do the muffler, and I got it back and retuned it, and now that's it's newly retuned, it hasn't done it again. And yes, I'd say that I'd rather have a saw richer than lean, but too rich is a bad thing too.

Of course now that I've said that...

Jeff

 

[CNYCountry]

Odd that I have had both problems, dieing on idle and running a lot better after two seasons on my ms310. Was out 2 days ago and really throwing a roostertail finally. Low idle - dealer today did some very minor carb adjust and increased idle speed a bit - same thing I was going to do.
Harry K

The increased power after run-in is definitely not something I'm seeing as a problem! The dealer said it would start running better after about 40-50 hours, in line with what a lot of people have said here, but I have intentionally run the saw hard, wide open and given it frequent periods to cool down with the intention of getting the rings seated quickly. It seems to have worked judging from the power output.

I was too busy to take it over this morning but will tomorrow, I am also sure it's sounding like a minor carb adjustment. I would mess with it myself but I don't have a tach and it's a very new saw.

After it stalls it seems harder to start, like there is not fuel directly at the venturi and the diaphragms in the carb have to suck up more, this is why I was thinking it was getting air or vapor locking. There are times when it idles at a perfect speed and other times when it idles way too low and stalls.

I will post results, it sounds like this is not the only occurrence of something like this and while it's not a major problem it is an annoyance.

Jeff, I'll have to get some information for Dean a little later, I'd like to open up the muffler at some point. The whole saw has to be shipped out there?

 

[fishhuntcutwood]

Jeff, I'll have to get some information for Dean a little later, I'd like to open up the muffler at some point. The whole saw has to be shipped out there?

No, you just ship him your muffler. He does the job, and sends it back.

And as far as the carb adjustment, I'd give it a shot yourself first. Not to avoid going to the dealer, but rather just to gain the experience yourself. A tach is nice, but this is an idle problem, and you'd be hard pressed to damage a saw by going too lean on the idle. I guess you could, but not nearly as easily as what you could at WOT. I'd play with it a little bit. Your condition sounds rich to me. I'd give the L screw clockwise (lean) turns at about 1/8-1/4 turn at a time. You've got limiter caps on there, so you can't go too far, and that's another reason I wouldn't worry about doing any harm. Depending on how much you adjust out of it, you may have to play with your H screw as well. Do a search on here for carb adjustments, and you'll find a bunch. And Madsen's website has a tutorial as well. Then, worse case scenario, you get the carb so far out of adjustment you take it into the dealer, and you're back where you are now, but with a little bit of experience under your belt.

Jeff

 

[fishhuntcutwood]

CNY- This is my muffler from Dean.

Jeff

 

[CNYCountry]

And as far as the carb adjustment, I'd give it a shot yourself first. Not to avoid going to the dealer, but rather just to gain the experience yourself. A tach is nice, but this is an idle problem, and you'd be hard pressed to damage a saw by going too lean on the idle. I guess you could, but not nearly as easily as what you could at WOT. I'd play with it a little bit. Your condition sounds rich to me. I'd give the L screw clockwise (lean) turns at about 1/8-1/4 turn at a time. You've got limiter caps on there, so you can't go too far, and that's another reason I wouldn't worry about doing any harm. Depending on how much you adjust out of it, you may have to play with your H screw as well. Do a search on here for carb adjustments, and you'll find a bunch. And Madsen's website has a tutorial as well. Then, worse case scenario, you get the carb so far out of adjustment you take it into the dealer, and you're back where you are now, but with a little bit of experience under your belt.
Jeff

This is all true, I took the saw there this morning before I read this and watched, he only turned the high and low screws very slightly along with bringing the idle up just a tiny bit. He said it was a little rich and wasn't topping out also. It does sound a little better now. I'll see what it does when I run it later.

The Madsen's tutorial is great, I had seen that and tuned other two cycle engines confidently but this one made me nervous since it was not cheap! I'll try the Madsen's method next time, thanks for the help!

 

[CNYCountry]

For what it's worth, I cut two 25" beech and a 22" elm up this weekend and did not have a single problem with stalling. The idle is just high enough that you can see the chain move a tiny bit once in a while at idle, shoes are just brushing the drum. Saw ran great.

 

[fishhuntcutwood]

If you can see you chain move at idle, even a very small bit, you'd probably be best off to tune that out. And that's easily done with your LA screw. Take it out (counterclockwise) the smallest bit, like an 1/8" or less to lower the idle RPM ever so slightly to take care of the condition you have. You probably won't even be able to hear a difference. Let your saw warm up a good five minutes or so before making any adjustments, as that does have an effect on a saw. After the warm up, it's likely you won't need to make those adjustments anyway. And if if it's turning as seldom as you describe, you're probably alright anway, but you'd still be on the high side of proper idle, and it's best your chain not turn at all when you're not on the trigger.

Jeff