Stihl MS261-CM 2020 4 months old scored piston???

[Stihl-Bummer]

Dealer cost of parts is far from retail cost.

Very true.

 

[Mad Professor]

For your occasional “milling” I’d recommend finding a good non mtronic saw like a 036/044. That way you can tune it rich and worry less about throttle control and more about cutting.


Sent from my iPhone using Tapatalk

TOO SMALL SAW

 

[JimmyT]

Maybe try a different oil, and run it richer than 50:1.

Ittybitty you are right on the money. Maxima K2 Oil at 32 to 1 with 93 Octane non-ethanol. Stihl-Bummer you have a big job so see need a big saw like a MS 661

 

[BradSt]

50:1 did NOT squeak that motor, even though I prefer a bit more oil. If the OP is sure he mixed 2.6oz to a gallon of gasoline, the failure lies elsewhere. Stihl orange bottle is perfectly fine, and won't cause a lube related failure on any stock saw. You do not need boutique racing oil in a stock chainsaw. If deviating from Stihl, anything JASO FD certified, and you're good to go.

Personally, I'd continue using the orange bottle for now, until you KNOW the rebuild is good to go. Less likely to have another fight on your hands, if you need further warranty work.

I've been riding high performance 2 stroke equipment for years, and have burned up my fair share of engines...snowmobiles, dirt bikes, PWCs, etc. Most of the failures occurred at less than full throttle...around 3/4-7/8ths. There can be a lean spot there...load is still very high, but fuel flow is reduced. Granted, these are all high output expansion chamber equipped engines, but the principle is the same.

 

[Stihl-Bummer]

Okedoke I will definitely now use full trigger. How long can I work the saw? Can a 50cc MS261C last an 8 hour day of cutting or is it to small to handle being used full throttle all day?

 

[kenton.a.frank]

TOO SMALL SAW

HE ISN’T DOING TRADITIONAL MILLING


Sent from my iPhone using Tapatalk

 

[dmb2613]

I would like to see the piston, I am almost sure it was from heat or something coming in the exhaust or intake. oil is not the issue. you can run a Stihl on straight gas for a long time before its toast . Stihl most likely did a good faith warranty, which is parts no labor .

 

[Stihl-Bummer]

I would like to see the piston, I am almost sure it was from heat or something coming in the exhaust or intake. oil is not the issue. you can run a Stihl on straight gas for a long time before its toast . Stihl most likely did a good faith warranty, which is parts no labor .

When I go pick it up in two weeks I will ask to see it. And take photos.

 

[86 350x]

I wouldn’t hack up the muffler until your warranty is over

 

[Stihl-Bummer]

I wouldn’t hack up the muffler until your warranty is over

Does cutting slits actually lower temps and allow it to operate better?

 

[JimmyT]

Exhaust Gills, cut them with a dremel. On the horizontal cuts use 1 1/4" cutting disc and a 1/2" worn down disc on the two small vertical cuts on each end. Then just bend the flap upward to 30 to 45 degrees. Now that little man can breathe.

Does cutting slits actually lower temps and allow it to operate better?

Does cutting slits actually lower temps and allow it to operate better?

 

[86 350x]

Yeah makes heat escape quicker

 

[Stihl-Bummer]

Yeah makes heat escape quicker

Thank you

 

[Stihl-Bummer]

So does a rip chain cut through the wood faster and take the stress off the chainsaw? Or does a rip chain cause the chainsaw to struggle? When I went to my local dealer they said the most aggressive chain I can use is the yellow in the photo is there a more aggressive chain that will cut the wood faster?

 

[SteveSr]

This is what the chainsaw died on. I really didn’t think this would cause a Stihl chainsaw so much trouble? Everything else I use the saw for was cutting logs and those white oak trees that I was talking about

Most common saw chain are designed for cross cutting. Milling is actually ripping and you should be using a ripping chain. The folks on the milling forum should be able to help you out. A good IR temp gun aimed at the cylinder will tell you when you are getting close to the danger zone. This is an over heating issue and not a lack of lubrication issue. The extra lube mostly benefits the bottom end.

 

[huskihl]

Most common saw chain are designed for cross cutting. Milling is actually ripping and you should be using a ripping chain. The folks on the milling forum should be able to help you out. A good IR temp gun aimed at the cylinder will tell you when you are getting close to the danger zone. This is an over heating issue and not a lack of lubrication issue. The extra lube mostly benefits the bottom end.

A milling chain is used for leaving a smoother finish, but it doesn’t cut faster and is actually less aggressive due to the blunt angles.

What the OP is doing is more like noodling than milling.

 

[tfp]

When I changed from standard chain to rip chain while milling with my 460 magnum with 30 inch bar, I went from using almost a tank of fuel per slab to getting close to 3 slabs cut per tank. That was in dead Australian hardwood 8 to 10 feet long.

When milling logs on the ground make sure you check your air filter frequently. I cleaned my outer pre filter every cut because the dust bouncing back up off the ground in dry hardwood was pretty crazy. If I can manage it I try to get them up off the ground now.

Keep the chain sharp and the gullets clean especially when the chain is getting on in age and number of sharpens.

 

[Stihl-Bummer]

Thanks you guys the more I learn about these chains I realize a lot of people on YouTube that are milling say don’t use a 30° angle. Is a 10 degree I just got done watching an MS 261 on YouTube using I think a 24 inch bar and it cut through a huge thick log no problem. I have now ordered a skip tooth chain and A ripping chain and will see which one does better. Putting a laser temp on the engine will also be a good idea I’ll stop halfway through the project measure the temperature and just make sure it’s not getting excessively hot.

 

[Stihl-Bummer]

A milling chain is used for leaving a smoother finish, but it doesn’t cut faster and is actually less aggressive due to the blunt angles.

What the OP is doing is more like noodling than milling.

Lol that’s what I thought I couldn’t imagine a 50.2cc saw not being able to noodle.

 

[BradSt]

Stihl 26RS or 26RM is what I'd be using. RM will stay sharper longer, but won't initially cut as aggressively. Make sure the chain color code is yellow, as the way you're cutting, you're using part of the tip. Green chain doesn't cut well on the sprocket tip.

Keep in mind, if you start using skip tooth chains, you're actually removing load from the saw. Lack of load is why you were running it part throttle. Full throttle with a moderate load is what I'd be shooting for. Stihl RS or RM chain will easily get you there, just make sure they are sharp and depth gauges are set correctly. Control the engine load by varying downward pressure and feed rate. When I'm milling with my 661, there is a specific engine pitch I shoot for...not screaming and not bogging.