Ethanol Damage of a Chainsaw

[1911]

Yesterday, fairly new Stihl gas powered lawn tool started acting up. Would only run above half throttle with choke on. Completely disassembled/cleaned carb and blew out fuel/vent lines. Never saw any thing to blame the problem on. Ran ok afterward.

Today a different, slightly older Stihl gas tool showed same symtems-WTF! On this one the design of the fuel tank made it easier to access the fuel pickup filter and tube. The rubber pickup tube in the tank has turned to jelley! It collapsed flat. When I tried to blow air through it, the hose swelled up and ruptured. This was not due to a blockage at one end. The blow out happened before the collapsed portion was fully inflated.

Then it dawned on me-Damned treehuggers/farm lobby (political?-sorry). Ethanol!

My search of FJR forum for ethanol related to small engines came up short (or I didn't look deep enough), but this: https://www.businessweek.com/lifestyle/cont...0514_058678.htm makes me think I'm on the right track.

I suspect thet the newer tool's sympton was caused by the same problem, but the newer rubber was successfuly uncollapsed, at least temporarily. NO MORE ethanol in the small engines for me YMMV.

 

[ShinyPartsUp]

Stihl makes great chainsaws, weed whackers, et al. I'm very surprised they had a failure like this. Have you talked to the dealer?

I've had problems from leaving fuel in the "tank" too long, but I run quality machines as well, and a little cleaning does the trick. Both 2 and 4 stroke engines have run fine for me for many years (except for a POS Polin I bought once). Nothing like melted rubber or anything major has gone wrong. I'm curious about the cause; ethanol might be a reason, I guess, or a hydrocarbon-sensitive hose was improperly used by Stihl?

 

[happyPuppy]

I had a riding mower that did a similar thing when Ethanol first started to be used a lot. I had to pull the carb and replace the rubber hoses, my fault for storing it with it in the tank. Now I run them dry.

 

[ShinyPartsUp]

I had a riding mower that did a similar thing when Ethanol first started to be used a lot. I had to pull the carb and replace the rubber hoses, my fault for storing it with it in the tank. Now I run them dry.

Good point. I burn off gas before storage for more than a couple weeks as well. The OP doesn't say if it was after prolonged storage with gas still remaining.

 

[YooperDick]

I had the same problem with an older Stihl leaf blower. Ethanol rotted the fuel lines. The dealer told me it was not an unusual problem and he had repaired numerous blowers and chain saws with the same issue. The fuel lines are now reformulated to accept the ethanol spiked gas.

 

[FJRay]

Its a common problem around here. Talked to the saw shop last week and they said if the fuel is over 60 days old to heave it and always run the saw dry before storing it.

When I first put the fuel cell on the FJR I used regular fuel hose and it went **** house and left me stranded in the middle of the night on a mountain pass. I replumbed it with marine grade coast guard approved ethanol fuel hose. Corn is for food not for fuel.

 

[dcarver]

Well then, another mystery of life for me solved. Same issue, Husqvarna saw.

 

[flying junior]

Indeed. When I moved out of the hills in 1972 I put my good ol' Homelite saw in the garage and prayed I'd never need it again after living in a house that burned 10 cords of wood a year, all cut by me. My M.O. had always been to dump the gas at the end of a day of using the saw, then run it until the last of the gas was sucked out of the carb. This was really a fairly new saw that I had always babied. It was utterly dependable.

I used it a few times in the ensuing years, then it sat idle until the kids were grown and one of the boys borrowed it 10 years or so ago. He brought it back the same day, complaining that something was wrong with it. He'd filled it with gas and it started right up, ran for a couple of minutes and then died and would not restart, no matter what he did.

No kidding. We looked in the tank and the pickup hose had just dissolved into tatters, and the carburetor was just oozing gas out of gaskets, etc. This was just as California started ordering those additives to gas to reduce emissions. It sure reduced emissions from that saw. It never took another breath.