New chainsaw purchase, but lost an old friend today...

[jb1390]

Whatever saw you have, do yourself a huge favor and don't use pump gas/oil mix in it. The new gas out there can destroy a saw's carburetor fast if it is not used every day. The carb parts get gummed up when the pump gas breaks down. Buy the pre-mixed "Ehtanol-Free" stuff at your local saw shop or the big box stores. It comes in 50:1 and 40:1 mixes so it can be used in whatever 2-stroke machine you have. The extra cost is worth the lack of maintenance headaches.

I was a career firefighter for 37 years and we started noticing saws would not run right all of the time. It turned out that the old-school pump gas and oil mixture we were using was damaging the saws. We switched to the per-mixed method and all of our saws, (over a hundred) saw an immediate reduction in carb problems and an increase in dependability. The vast majority of the saws were Stihl, but the advice is universal. My home saw is a Stihl Farm Boss.

At $10 a quart or whatever they are charging for that pre mixed stuff, it'd be crazy to run it all the time for many people. If you're a user that rarely uses your saw, and most of the time it sits on a shelf, then maybe it makes sense. For firefighting, the increased cost is probably a drop in the bucket.

FWIW the only consistent issue I've seen from pump gas is destruction of the fuel lines. Using a good 2 stroke oil helps, but doesn't eliminate the problem. I've heard that some newer saws are including better fuel line to eliminate the issues with ethanol.

 

[JRobyn]

Destruction of the fuel lines AND (more importantly) the rubber carburetor diaphragms that are both the fuel pump and fuel metering. Late-model diaphragms are more resistant to ethanol issues but definitely still not immune.

- Jay

 

[Jstpssng]

Whatever saw you have, do yourself a huge favor and don't use pump gas/oil mix in it. The new gas out there can destroy a saw's carburetor fast if it is not used every day. The carb parts get gummed up when the pump gas breaks down. Buy the pre-mixed "Ehtanol-Free" stuff at your local saw shop or the big box stores. It comes in 50:1 and 40:1 mixes so it can be used in whatever 2-stroke machine you have. The extra cost is worth the lack of maintenance headaches.

I was a career firefighter for 37 years and we started noticing saws would not run right all of the time. It turned out that the old-school pump gas and oil mixture we were using was damaging the saws. We switched to the per-mixed method and all of our saws, (over a hundred) saw an immediate reduction in carb problems and an increase in dependability. The vast majority of the saws were Stihl, but the advice is universal. My home saw is a Stihl Farm Boss.

That's good advice for when you aren't using your saw frequently. I go through spells when I'm burning a couple gallons a weekend; other times I'm pouring old gas into my burn pan to get rid of it.
Another plan is to go to the local airport, they don't allow ethanol in aviation fuel.

 

[Loadstar]

My 08 spends much time in the elements and runs pump gas and still works fine just like much of my equipment. Once a carb kit and hoses are changed to ethanol friendly stuff it's not a problem.

 

[jb1390]

Destruction of the fuel lines AND (more importantly) the rubber carburetor diaphragms that are both the fuel pump and fuel metering. Late-model diaphragms are more resistant to ethanol issues but definitely still not immune.

- Jay

Might be an issue on older saws, I'm not sure. I've only been cutting since around 2003, and haven't had any issues with diaphragms or anything in the carburetor degrading from using pump gas. The fuel lines have been a fairly consistent problem for me across many machines. I've also, for what it's worth, always used Husqvarna brand name synthetic oil. From what I understand, it's supposed to stabilize the fuel to some degree.

 

[KubotaToy]

A quick update on my ms250, they were not able to rebuild it but the blade and chain survived. Looks like I get to shop for a 250ish size saw now.

As far as fuel, I only use ethanol free gas for all my small engines, for the chainsaws I usually only mix a gallon at a time. I either use it up in about a month or I pour it in my dump truck gas tank. The dealer (whom I trust a lot) said ethanol will not hurt any chainsaw built in the past few years built for the US market but as long as I can get straight gas I will use it. I ran methanol in my IMCA dirt modified for 15 years, the real problems were water absorption and corrosion of metals in the fuel system.