MS-250 Lean

[KD5UDB]

Hi Guys,

I am new here, but have been reading here for quite a while. I have been running mostly small saws for 30 years and recently purchased an MS-250 from my local dealer to work on a large gum stump in my mothers back yard.

First time I used the saw it acts like it's sagging out, then quits in a longer cut like it's running too lean. The High mixture needle is set CCW to the richest setting now and it still sounds very lean, still quits in a long cut. I grabbed the old Poulan after this, but the question is, is tis common, if I haul it back to the dealer can they do anything with the limiter. Could this be something else all together like the engine pulling air somewhere else. Also, it go warm here, about 90 F the day I was out working on that stump.

Remember, this is a brand new saw with less than a tank of gas through it.

Thanks ahead of time.

Chris in Baton Rouge, La

 

[Log Splitter]

Welcome to AS, KD5UDB!

I'm not a saw tech, but my best advice for you is to get that saw back to the dealer and have him fix it. A new Stihl should not be dying in the cut, even though taking stumps out works a saw really hard. Tell your dealer you had to finish the job with a Poulan after the Stihl died.

 

[KD5UDB]

Thanks Log Splitter !

Yes, I think I will have to bring it back. Didn't seem right to me either to be quiting on me, and it sounds very lean. I actually spent more time clearing and weed eating around that stump than I did sawing before dark Sunday evening. I had just started on the butress (Is this correct?) area around the base of the stump.

When the land was cleared behind the back property line, the workers were pulling out stumps with dozers, and leaving them cut high to do so. They didn't pull this stump up because it would have taken half the yard with it. I just want to knock it down to ground level to be able to clean up the area.

Will see what the dealer says, I will just have to make sure that he realizes that it needs to be under a load to quit.

Am I to assume that these saws are better a little on the rich side and lean out under load like other saws I have used?

Chris

 

[Wismer]

Chris,

I think it's a no-brainer to take that saw back to the dealer, especially if it's new. Any dealer who wants your business will go out of their way to help.

Let us know how it goes


Craig

 

[Lakeside53]

It is abnormal -take it back. It might be something wacky likea twisted fuel line, or something more serious.

 

[KD5UDB]

Yes, I think everyone here is correct. I have a meeting with a roofer and think that while I am at the house I'l grab the saw and drop it back off to them on the way back to work.

Will post an update later .........

Chris

 

[KD5UDB]

Update

Well, looks like it was lean as well as a timing issue (at least according to the dealer). All running well now though, it has the slight burble until you start cutting in something stout then smooths out and cuts. No more quiting in the middle of a cut and I presume that this is the way it should have been to start with.

Thanks again guys !

Chris

 

[Lakeside53]

Timing issue? Hmmm :monkey:

 

[Christman]

andy have you seen alot of 250 lean out. how would timing make it lean out?

 

[KD5UDB]

Thats what I thought

I was skeptical too. Are there adjustement slots on the pickup/coil on these saws ? Haven't had it long enough to even look.

I think that he pulled the cap off the high needle, backed it out a little, and put the cap back on. To me, (and I have been adjusting carbs on small engines for years) it just sounded like it was heating up and going lean enough to quit under load. Now it just slightly fat after starting and warming up. Seems to be just right in a longer cut now, no sagging and plenty of power.

Chris

 

[KD5UDB]

Lean from the getgo

Bye the way, this saw sounded dead lean from the first time it was started. Couldn't get a slightly rich burble out of it even from a cold start with the high needle all the way ccw on the stop.

Probably the factory had it set that way.

Chris

 

[Lakeside53]

Even if the factory did have something set wrong, the dealer is supposed to check the saw when he fires it up. But, sometimes it is hard to detect these problems out of the box. Not many dealers put them in wood (we don't).

As for timing - there is no adjustment. The only way the "timing" can get off is 1) the coil is bad (for example - stuck in retard), or 2) the cast-in flywheel key has sheared.

 

[KD5UDB]

Thanks Lakeside !

Thanks on that info Lakeside.

They never put it in any wood, I had cleaned it up before brining it back in. Looks like they just richened it up a bit. Runs good now.

Could be the altitude difference and the fact that it's already 90 deg and 100 % humidity here ??

Chris

 

[ShoerFast]

Chris

Your loosing about a 1/4 HP 90 Deg. and 90 Deg. dew point. Do a muff mod and you may get all that back and the saw will run a lot cooler!

( I used 1000' in this caulcuator : http://wahiduddin.net/calc/calc_hp_dp.htm

your working at a virtual 100 Deg's with what humidity, and the saw dose get less cooling with the lighter - hotter air , and will have 91.5% of it's rated power ... or 3HP stock X .915 = 2.745 HP )

 

[SawTroll]

Hi Guys,

I am new here, but have been reading here for quite a while. I have been running mostly small saws for 30 years and recently purchased an MS-250 from my local dealer to work on a large gum stump in my mothers back yard.

....

Welcome tom AS! :biggrinbounce2:

...but cutting large stumps with a 250 sounds like overworking the saw to me, specially if it is brand new.

 

[ShoerFast]

Welcome tom AS! :biggrinbounce2:

...but cutting large stumps with a 250 sounds like overworking the saw to me, specially if it is brand new.

And what would you suggest?

Chris,

Yes welcome to the site, there are some things you can count on*,,,, and here he comes!


Let's all guess,,, a 361? lol


*The Great Saw Troll dose not take money as an issue when buying a saw

 

[SawTroll]

And what would you suggest?

Chris,

Yes welcome to the site, there are some things you can count on*,,,, and here he comes!


Let's all guess,,, a 361? lol


*The Great Saw Troll dose not take money as an issue when buying a saw

Well, the term "large" isn't defined here, so I refuse to point at a spesific size of saw........:chainsawguy:

 

[KD5UDB]

Well,

It's large compared to a baby echo, and yes, I probably will overwork it bit on that stump, but then again it may not get used much unless we get another hurricane and have more trees down again. I will use it some when I trim trees at my property and one other property every year

A lot of times I ride down the road and find oak limbs that are already down to just throw in the truck and cut up at home for outside firepit wood. Most times this just calls for a baby saw.

Thanks again guys, will be reading here because it's all interesting and theres something to learn.

Chris

 

[KD5UDB]

Another Update

Saw went lean and quit on me yesterday making a horizontal cut. Thought I ran out of gas, so checked the gas and found the tank half full. Said to myself "what the heck", then on looking more closely at it I realized that the clunk weight (model airplane terms for fuel pickup/screen) was doubled back and near the fuel fill opening. This puts it out above the fuel with a half empty tank when the saw is on its right side.

Someone here mentioned a twisted fuel line. Well, he was close, that can make for a world of trouble. Besides being too lean out of the box, this saw also had this problem.

Probably easily solved.

Chris

 

[Lakeside53]

Yep.. seen that and in a 250!


Make sure you (or your dealer) stuff the filter/hose back into the tank properly... That may have been your orginal "lean out of box" problem...