40:1 or 50:1 mix on 372XP

[firewoodpanaca]

I am running 2 372XP husky and cutting 250-300 cords a year. Also run a 391 Stihl and a couple of 455s when the stihl or 372 are down. I have run 440 stihls and a 441 stihl over a 20 year period of cutting. I am curious as to the advantage some of you get by running 40:1 instead of 50:1. I run 50:1 and use a synthetic oil to mix. Does running 40:1 give you longer saw life or why do some of you run 40:1?? Thanks in advance.

 

[Trx250r180]

If the saw is stock ,50 to 1 is fine ,if the compression has been raised and cylinder hopped up ,40 to 1 will help the extra load on the bearings .

 

[BroncoRN]

I mix 40:1 Echo PowerBlendX on everything I own. Never had an issue with my 372xp.

 

[bmwpowere36m3]

No difference with modern oil... tuning will play a larger factor.

 

[SS Sniper]

We've been running 32:1 in all the saws for awhile, which includes a 372xp and 371xp among several other stock saws.

It's definately enough oil, but running a saw rich won't hurt it none, to a point of course.

If I recall right, Randy said something along the lines of the bottom end of the 371xp/372xp series saws needing significantly more oil than 50:1 can offer.

 

[Full Chisel]

The guys that open these saws up for a living report better oil saturation in the lower end with saws that have run 40:1 or 32:1 over 50:1. Cheap insurance, IMO.

 

[blsnelling]

The guys that open these saws up for a living report better oil saturation in the lower end with saws that have run 40:1 or 32:1 over 50:1. Cheap insurance, IMO.

The 372 is known to benefit from more oil than 50:1, particularly the bottom end. I run 32:1 in all of my saws.

 

[nitehawk55]

Running a non ethanol high test fuel is important too .
I run 40:1 in all mine .

 

[blsnelling]

Running a non ethanol high test fuel is important too .
I run 40:1 in all mine .

His fuel isn't going to go stale with the amount he's burning. E10 burns fine.

 

[nitehawk55]

His fuel isn't going to go stale with the amount he's burning. E10 burns fine.

Will if he stores it in the saw for a period of time . I'd rather have non ethanol fuel over E10 anytime then risk it gunking up the fuel system , cheap insurance .

 

[HuskStihl]

cheap insurance .

It's really not cheap insurance. For me to run "high test ethanol free" is probably a 4-5 dollar a gallon investment, not counting the PITA factor of acquiring said fuel. 87 e10 is about 1.90. If I'm using my 394, that may be 2-3 gallons a day. At the current costs of carb kits and Tygon, e10 would have to foul a carb/line a little more than once a week for me to break even on the fuel. It has been several years since I replaced a fuel line or refreshed a carb. If you run a saw for an hour, then let it sit for three months routinely, then it would be cheap insurance

 

[nitehawk55]

Well that's not the case in all areas but my condolences to your situation.
I use Shell V power 91 here and it's just a bit extra . Just threw it out there , we know a lot of people have problems with ethanol in small engines that is stored for a time .
I should add that gas up here is close to $1 per liter which is 3.8 x $1 = 1 US gallon .
Thought you fellows had it good in TX , seems the gas prices were pretty good when I took my youngest son to A&M some years ago

 

[HuskStihl]

Gas is cheap, but efree out of a pump is not available.

 

[ArthurB]

I found that my 372XP ran too hot at 50:1 (Husq high-spec oil) - this was cutting hardwood trunks

Contacted dealer who recommended 40:1 or lower

I've gone to about 35:1, and find it runs much cooler - no smoke

 

[Andyshine77]

The difference in engine heat between 50:1 40:1 32:1 is nominal, the heat difference comes down to tuning. With that said, 372's have somewhat weak bottom ends, so yes not oil will keep them together longer.

Sent from my HTC One_M8 using Tapatalk

 

[ArthurB]

The difference in engine heat between 50:1 40:1 32:1 is nominal, the heat difference comes down to tuning. With that said, 372's have somewhat weak bottom ends, so yes not oil will keep them together longer.

Sent from my HTC One_M8 using Tapatalk

There was an enormous difference in heat when the saw was running with 50:1 vs 40:1 or 35:1

When plugging hard, way too much heat - to the point where I wasn't comfortable to continue using the saw

Completely resolved by raising the mix

I've encountered the same thing with a 2-stroke trials bike, which I now run much richer

 

[Little Al]

This is a topic that will I guess never get resolved there are the 50 & north to 1 believers & the other end the 40 & south to 1 group Both side quote X # of years trouble free use with their particular mix, & some take to task the posters that differ from their way of thinking I think it's a run what suits & you are happy with & any different mix they like let them carry on I have given up quoting why I run the mix I do & now adopt the do as you like to mix ratio's.

 

[Full Chisel]

There was an enormous difference in heat when the saw was running with 50:1 vs 40:1 or 35:1

When plugging hard, way too much heat - to the point where I wasn't comfortable to continue using the saw

Completely resolved by raising the mix

I've encountered the same thing with a 2-stroke trials bike, which I now run much richer

Technically a richer oil mixture should run hotter. More oil in the mix means less volume of fuel in the charge. The primary cooling mechanism of an air cooled 2 stroke is the evaporative cooling effect of the incoming fuel mixture.

 

[Full Chisel]

Well that's not the case in all areas but my condolences to your situation.
I use Shell V power 91 here and it's just a bit extra . Just threw it out there , we know a lot of people have problems with ethanol in small engines that is stored for a time .
I should add that gas up here is close to $1 per liter which is 3.8 x $1 = 1 US gallon .
Thought you fellows had it good in TX , seems the gas prices were pretty good when I took my youngest son to A&M some years ago

I run Shell V Power 93 but it ain't E-free around here...I don't worry about it too much, I just make sure to turn over my tanks within a month.

 

[Andyshine77]

There was an enormous difference in heat when the saw was running with 50:1 vs 40:1 or 35:1

When plugging hard, way too much heat - to the point where I wasn't comfortable to continue using the saw

Completely resolved by raising the mix

I've encountered the same thing with a 2-stroke trials bike, which I now run much richer

It is a known fact, adding more oil slightly increases engine temperature. The difference you saw was caused by a change in air fuel mixture, or it is simply in your head. Different fuel, and environmental changes will cause the mixture to change, but it was not cause by simply adding more oil.