Stihl ms 362cm piston browning

[Zooman362]

Hello,
Want to share some strange things about piston on my ms 362cm.. Chainsaw is one year old and has about 20 tank's of work. Used husqvarna xp oil 3 tanks, rest was ls+, and stihl ultra oil for mix with petrol 95 with 5% ethanol, always fresh mix.
So please advise what is wrong, chainsaw is working properly for now. And i have old stihl 17 years, piston look like new...

 

[alexcagle]

Looks normal to me.
Browning is usually caused by short cuts which leave the cylinder wet with fuel.

 

[farmguywithasaw]

What do you mix your oil too? It doesn’t look bad to me. Could be because you’re a tad heavy on the oil.

 

[ZeroJunk]

Stop taking your muffler off and looking at your piston.

 

[Zooman362]

What do you mix your oil too? It doesn’t look bad to me. Could be because you’re a tad heavy on the oil.

1:45

 

[Zooman362]

Looks normal to me.
Browning is usually caused by short cuts which leave the cylinder wet with fuel.

I use it like a allround chainsaw, for bucking 25" logs and limbing 5" branches.
Hopefully is all ok, but i was little scar for piston

 

[cookies]

Carboning like that comes from a hot piston not coated in enough oil, thats a strato engine and they need a minimum of 40-1 if not 32-1 due to their reduced fuel consumption and fresh air savaging.

 

[Zooman362]

It's just that every piston I see on web that's in good shape and with lot's of hours doesn't have this browning thing on it... Trying to understand why is this happening and can I continue working?

 

[farmguywithasaw]

It's just that every piston I see on web that's in good shape and with lot's of hours doesn't have this browning thing on it... Trying to understand why is this happening and can I continue working?

It’s a coating of oil “burnt” onto the piston. Similar to seasoning a cast iron pan. I wouldn’t worry about it. If you have ocd of such things u can use echo red shield oil. It may cut down on it. Like I said I wouldn’t worry about it. I have seen this on saws I’ve torn down. Also let the saw idle for a bit and cool down befbefore you shut it would also help

 

[huskihl]

 

[SteveSr]

Hello,
Want to share some strange things about piston on my ms 362cm.. Chainsaw is one year old and has about 20 tank's of work. Used husqvarna xp oil 3 tanks, rest was ls+, and stihl ultra oil for mix with petrol 95 with 5% ethanol, always fresh mix.

There have been reports of similar issues when using Stihl Ultra oil which is only JASO "FB" rated and was designed for the Stihl 4-mix engine. You may get better results with a JASO "FD" oil like Echo Red Armor.

 

[Zooman362]

Husqvarna ls+ semi synthetic is rated fd.. That's most I've used... Xp synthetic is also fd.
OK im glad that's nothing to worry about, thanks

 

[farmguywithasaw]

There have been reports of similar issues when using Stihl Ultra oil which is only JASO "FB" rated and was designed for the Stihl 4-mix engine. You may get better results with a JASO "FD" oil like Echo Red Armor.

I don’t use Stihl ultra. I use there premium stuff in the white bottle. I like it because it has a fuel stabilizer in it.

 

[singinwoodwackr]

Stop taking your muffler off and looking at your piston.

Will it make you go blind?

 

[Vintage Engine Repairs]

Richard Flagg has covered this quite extensively with Stihl Ultra.

Edit:

 

[Zooman362]

I've watched Richard video about ultra, that's why I switched to xp+... 45:1

 

[Oletrapper]

Hello,
Want to share some strange things about piston on my ms 362cm.. Chainsaw is one year old and has about 20 tank's of work. Used husqvarna xp oil 3 tanks, rest was ls+, and stihl ultra oil for mix with petrol 95 with 5% ethanol, always fresh mix.
So please advise what is wrong, chainsaw is working properly for now. And i have old stihl 17 years, piston look like new...
View attachment 1122661View attachment 1122662View attachment 1122663View attachment 1122664

Have no idea why you removed the muffler to begin with but I would put my money on the ethanol. Worse thing they ever did and it is hell on a 2 stroke. Especially hard on the carbs. They also lie about the content in fuel. Lord only knows how much there really is in there. JMHO OT

 

[farmguywithasaw]

Will it make you go blind?

No but if you put your finger in the exhaust port and turn it over it hurts

 

[Lightning Performance]

Have no idea why you removed the muffler to begin with but I would put my money on the ethanol. Worse thing they ever did and it is hell on a 2 stroke. Especially hard on the carbs. They also lie about the content in fuel. Lord only knows how much there really is in there. JMHO OT

It's oil related not fuel. Fuel will not color a piston on the sides. Trash Ultra will. I bought enough used Stihls saws running the silver bottle they sell with a silver to know better.

It was explained above incase you missed it.

Bad fuel is why I lost two engines this year in August and September. One two stroke weed whip and one small four-stroke Honda 5.5 pressure washer. Suspected Eth20% or more. They went lean, got too hot and sized the piston. 40-1 mix of top grade oil. The washer was just gas not mixed. The water in the fuel obviously leaned these out so the piston stuck during shutdown.

 

[lone wolf]

It's oil related not fuel. Fuel will not color a piston on the sides. Trash Ultra will. I bought enough used Stihls saws running the silver bottle they sell with a silver to know better.

It was explained above incase you missed it.

Bad fuel is why I lost two engines this year in August and September. One two stroke weed whip and one small four-stroke Honda 5.5 pressure washer. Suspected Eth20% or more. They went lean, got too hot and sized the piston. 40-1 mix of top grade oil. The washer was just gas not mixed. The water in the fuel obviously leaned these out so the piston stuck during shutdown.

Damned EPA caused it!