2 cycle premixed fuel

[Tankie]

I’m about to buy a new saw that uses 50:1 fuel mixture. I have about 3/4 gallon of 40:1 premix. Would it hurt anything running the 40:1 in a saw requiring 50:1? I don’t want to waste this stuff and I have no other 2 cycle equipment.

 

[jasent]

Tune accordingly and it will be fine. If not retuned it will run lean. More oil means less fuel per ounce of mix. Tune to fuel used and your fine

 

[Tankie]

Tune accordingly and it will be fine. If not retuned it will run lean. More oil means less fuel per ounce of mix. Tune to fuel used and your fine

Thanks, that is what I thought but I wanted to make sure.

 

[Tankie]

Anybody else have an opinion about this? I’m tempted to just try running the 40:1 without retuning because this is a brand new saw and is under warranty. Maybe even mixing some of the 40:1 with the 50:1, maybe about a half tank of each.

 

[jasent]

Why? Tuning is so simple why risk it?

 

[Tankie]

I don’t know anything about the tuning of a chainsaw and I wouldn’t want to void the warranty by changing the tune of the saw.

 

[Bob Hedgecutter]

I don’t know anything about the tuning of a chainsaw and I wouldn’t want to void the warranty by changing the tune of the saw.

This is an interesting quandary- if indeed you do not know about tuning of a chainsaw, obey the warranty to the letter of the law and probably prepare yourself to use it- because most new saws come factory lean or on the very edge of no error margin.
Tip the 3/4 gallon of 40:1 into a gasoline motor vehicle or mower and use it that way.

Do you have the 40:1 left over because your last saw burned up and you were told it was cheaper to buy another new than to have the last repaired?
I have never used premix- but then again we do not have E fuel either.

 

[Tankie]

Yes, I have the premixed 40:1 left over because my other saw wasn’t worth fixing. It was low compression, wasn’t burnt up. I was tired of messing with it. It was an old cheap saw to start with.
I’ve been wanting a Stihl for a long time and finally got me a new MS250 as a replacement as I seldom cut anything very big.

 

[Bob Hedgecutter]

Yes, I have the premixed 40:1 left over because my other saw wasn’t worth fixing. It was low compression, wasn’t burnt up. I was tired of messing with it. It was an old cheap saw to start with.
I’ve been wanting a Stihl for a long time and finally got me a new MS250 as a replacement as I seldom cut anything very big.

Do you still have the low compression saw- be interested in a photo of the piston through the exhaust post.

 

[Tankie]

Yes, I still have saw. I actually find it hard to believe that it has low compression because I just put new piston, cylinder and ring on it. I’m just going by what a saw mechanic told me. I have only gotten it to start and run for a few seconds at a time, never long enough to even reset the choke.
As I said I’m tired of messing with it. I’ll try to get a picture soon.

 

[jasent]

Carb has limiter caps so you can’t void your warranty tuning to your fuel of choice.

 

[jasent]