40:1 to rich?

[MS460WOODCHUCK]

I run 40:1 full synthetic in all my saws (mostly newer stihls).

I have a guy who is the mechanic in a saw shop telling me I will burn up my rings from running it to rich that I should run 50:1. That he has seen 7 460's and 3 660's already this year come in with toasted top ends from 40:1 running to rich and building up carbon in the exhaust port and the carbon ending up back in the top end.

He also told me that running 40:1 makes your saw run hotter than 50:1 because the oil burns hotter that the fuel.

I've opened my mufflers up and have seen no sign of carbon but I've only ran about 10 gallons since switching from 50:1 to 40:1.

I'm not looking to get flamed for a oil thread but this really has me thinking does 40:1 make my saws run hotter than 50:1? Should I be running at 50:1? Has anybody that works on saws daily seen any problems with 40:1 like he's saying?

 

[parrisw]

No the guy telling you this don't know ****. I find synthetic burns more complete, thus less carbon, the regular stihl oil you will carbon up more. But it takes a long time to carbon up a saw, keep it tuned right and you wont have a problem. If it starts getting carbon'd up you need to decarbon before it causes a problem. Most people abuse their stuff, and perform no maintenance, thus burning up top ends.

 

[Hedgerow]

No the guy telling you this don't know ****. I find synthetic burns more complete, thus less carbon, the regular stihl oil you will carbon up more. But it takes a long time to carbon up a saw, keep it tuned right and you wont have a problem. If it starts getting carbon'd up you need to decarbon before it causes a problem. Most people abuse their stuff, and perform no maintenance, thus burning up top ends.

+1...

 

[Kmaxwell102]

I hope not because ive been doing exactly what your doin. Runnin 40:1 in my new 460. I wish the high end of the carb would actually ajust out... Worries me a little sometimes

 

[Simonizer]

I run 40:1 full synthetic in all my saws (mostly newer stihls).

I have a guy who is the mechanic in a saw shop telling me I will burn up my rings from running it to rich that I should run 50:1. That he has seen 7 460's and 3 660's already this year come in with toasted top ends from 40:1 running to rich and building up carbon in the exhaust port and the carbon ending up back in the top end.

He also told me that running 40:1 makes your saw run hotter than 50:1 because the oil burns hotter that the fuel.

I've opened my mufflers up and have seen no sign of carbon but I've only ran about 10 gallons since switching from 50:1 to 40:1.

I'm not looking to get flamed for a oil thread but this really has me thinking does 40:1 make my saws run hotter than 50:1? Should I be running at 50:1? Has anybody that works on saws daily seen any problems with 40:1 like he's saying?

I agree with Will. 40:1 is fine. Oils have improved dramatically over the years so 50:1 will work but 40:1 is what I recommend to all of my pro customers.

 

[MS460WOODCHUCK]

These opinions make me feel better for sure. Thanks for the imput guys, I really thinking about going back to 50:1 but it looks like I'll be staying at 40:1.

 

[Cstratton]

I run 40:1 full synthetic in all my saws (mostly newer stihls).

I have a guy who is the mechanic in a saw shop telling me I will burn up my rings from running it to rich that I should run 50:1. That he has seen 7 460's and 3 660's already this year come in with toasted top ends from 40:1 running to rich and building up carbon in the exhaust port and the carbon ending up back in the top end.

He also told me that running 40:1 makes your saw run hotter than 50:1 because the oil burns hotter that the fuel.

I've opened my mufflers up and have seen no sign of carbon but I've only ran about 10 gallons since switching from 50:1 to 40:1.

I'm not looking to get flamed for a oil thread but this really has me thinking does 40:1 make my saws run hotter than 50:1? Should I be running at 50:1? Has anybody that works on saws daily seen any problems with 40:1 like he's saying?

HUH??? If anything, more oil just equals a leaner air/ fuel ratio. Where do these people come from? I have ran 40:1 in all of my 2 strokes for 20 years. I would love to see the engines this guy says he worked on to come up with this theory!

 

[Andyshine77]

Like others have said, maintenance key. I run my mix at 32:1 without any issues.

 

[atvdave]

HUH??? If anything, more oil just equals a leaner air/ fuel ratio. Where do these people come from? I have ran 40:1 in all of my 2 strokes for 20 years. I would love to see the engines this guy says he worked on to come up with this theory!

Agree.... More oil in the mix=leaner Air/fule ratio, in turn will make your saw run hotter.

However many people run 40:1 with-out any issues.

 

[pajeepman]

I've been in the tree care industry for 8.5 years and for 5 years we ran 40:1. We have been running 50:1 since then. No difference noticed. The only saw that died was a 372xp and it died when running 50:1. I gotta try and buy it from my boss and put a big bore kit in it.

 

[pele55]

oil mix

i have been working on chainsaws for over 20 years now. we run av gas with amsoil sabre mixed at 50 to 1 in everything and have had no problems.. the saws run better and more efficient.. i have seen many a spark arrestor screen plug up from a combination of the air fuel mix being to rich and the oil to fuel ratio being to rich

 

[Finch]

I have been running 40:1 for as long as I can remember..Never once had a trouble with any my 2 strokes becouse of it.Now I run full synthetic.(Stihl Ultra)..I run even that at 40:1..Run full synthetic I love it. Thanks for the advice of this forum from nice ppl I now I run synthetic..I get about 3 dollars cheaper then std oil from stihl at my stihl dealer I buy 5 to 6 packs at a time ..But we are good friends..

Finch

 

[Cstratton]

And for the carbon being sucked into the cylinder? Even a tuned pipe has a hard enough time pulsing the air/ fuel charge back into the cylinder. Let alone solid material that could fall between the piston/ cylinder and wreck it.

 

[PLMCRZY]

The only reason i run 40:1 is cause you told me woodchuck!

 

[Chopper G]

Stihl could sell more of their premium oil if it suggested 40:1.
If 40:1 made the saws more durable/reliable or perform better, it would be in Stihl's interest to suggest that ratio.

But Stihl suggests 50:1, even during break-in.

Not knocking anybody, just curious - what is it that people seek to gain via 40:1 (or even richer) and how does the richer mix acheive that goal?

Thanks

 

[eMGunslinger]

Agree.... More oil in the mix=leaner Air/fule ratio, in turn will make your saw run hotter.

Not to seem like a smart*$# but oil is fuel....just kinda crude

 

[Cstratton]

Not to seem like a smart*$# but oil is fuel....just kinda crude

So is carbon! Just cruder! LOL

 

[atvdave]

Not to seem like a smart*$# but oil is fuel....just kinda crude

Take a match to a cup of Gas, then take a match to a cup of oil... see what happens...

No wait.. do the oil first...

 

[eMGunslinger]

Take a match to a cup of Gas, then take a match to a cup of oil... see what happens...

No wait.. do the oil first...

I know I know it was more of a joke then all seriousness i promise, but it would also depend on the surface volume of the gas and oil as well

 

[parrisw]

I agree with Will. 40:1 is fine. Oils have improved dramatically over the years so 50:1 will work but 40:1 is what I recommend to all of my pro customers.

Thanks Simon. Yes I run 40:1 in all my saws since most of them are modded.

HUH??? If anything, more oil just equals a leaner air/ fuel ratio. Where do these people come from? I have ran 40:1 in all of my 2 strokes for 20 years. I would love to see the engines this guy says he worked on to come up with this theory!

Yes, when running 40:1 you have less fuel then at 50:1

i have been working on chainsaws for over 20 years now. we run av gas with amsoil sabre mixed at 50 to 1 in everything and have had no problems.. the saws run better and more efficient.. i have seen many a spark arrestor screen plug up from a combination of the air fuel mix being to rich and the oil to fuel ratio being to rich

:msp_thumbup::msp_thumbsup: Yes! I run Amsoil Sabre, it rules!!! Best I've ever used.

And for the carbon being sucked into the cylinder? Even a tuned pipe has a hard enough time pulsing the air/ fuel charge back into the cylinder. Let alone solid material that could fall between the piston/ cylinder and wreck it.

The problem is it builds up in the ex port and actually can rub on the piston scoring it.