Gas for chainsaw...

[Oaktree]

I had a low quality gas experience with my first car (1 tank full!), that triggered new plugs and new fuel filter($$). The week prior, I had just done a tune up and replaced the plugs which were ok, but it was time. A tank of bad gas later, I was convinced that I had missed something badly in the tune up. When I checked, the plugs were black and covered in gunk.

Do those kinds of things still happen?
I had an experience similar to yours back in the mid-70s. Happened on a cross-country road trip, got a tank of bad gas somewhere along the way, barely made it home the car was running so badly. Fuel filter was full of gunk, as was the carburetor. Even after replacing the filter & rebuilding the carb there were still driveability issues (most notably mild surging at certain speeds). Turns out the pre-filter in the tank was also gunked up. Once I cleaned that, all was well.

Never had anything similar happen since.

 

[CalG]

There is a motorist axiom that goes,

"never buy gas at a filling station that has a delivery truck parked over the in ground tank access ports"

 

[ponytug]

Do those kinds of things still happen?
I had an experience similar to yours back in the mid-70s. Happened on a cross-country road trip, got a tank of bad gas somewhere along the way, barely made it home the car was running so badly. Fuel filter was full of gunk, as was the carburetor. Even after replacing the filter & rebuilding the carb there were still driveability issues (most notably mild surging at certain speeds). Turns out the pre-filter in the tank was also gunked up. Once I cleaned that, all was well.

Never had anything similar happen since.

Admittedly, my story is that vintage, though I did have some bad fuel episodes in the eighties. Mostly, I learned my lesson. I also think that more recent pollution vapor control measures also help keep moisture out of storage tanks, limiting corrosion and microbial growth.

I hadn't heard the delivery truck axiom. I have been told to buy fuel at stations with high sales volumes, and never to pump fuel if there is a fuel delivery happening as the delivery stirs up the tank and any sediment therein.

All the best,

Peter

 

[mo1]

Doesn't 91 octane have more ethanol than 87 cause it's used as an octane booster? I use whatever non ethanol fuel is available for my infrequently used carbureted two strokes.

It depends. Where I live, the answer is no, premium has no more ethanol than regular and actually may have less ethanol in it. The state mandates 10% ethanol in all gas under 91 octane and anything 91+ octane can have anywhere between no ethanol and 10% ethanol. In practice premium here is either 10% ethanol, or no ethanol and sold at a big premium.

I always thought ethanol was added to gas to help with pricing/shortages of oil and our (at one time?) immense ability to produce corn. Or perhaps to help subsidize the corn farmers?

I didn't know it was used or able to raise any octane levels??

Probably showing my ignorance in all of the above.

Ethanol has a very high octane rating. Adding it at low concentrations is like mixing in 115 octane fuel, adding 10% to regular gas increases the octane by 2.5 points. Adding it in higher concentrations depends on the engine it's run in. E85 is roughly 105 octane in a naturally aspirated engine, about 115 octane in a forced aspiration and aftercooled engine, and 130+ octane in a forced-aspiration non-aftercooled engine. Ethanol takes a bunch of heat to vaporize which significantly lowers charge air temps, which is a big component of power production in forced-aspiration setups.

Ethanol was initially introduced to reduce MTBE as an oxygenate to reduce emissions due to the previously-mentioned groundwater contamination with MTBE. The discussion regarding corn subsidies came a bit after that. The fact that it raised octane levels did not appear to be a factor initially as the initial ethanol blend here was 89 octane mid-grade and that was it. This was regular 87 octane with a little under 10% ethanol added. If it was about raising octane they would have added ethanol to all grades right off the bat and you would have seen them add ethanol to 92-93 octane premium to make 94-95 octane super-premium. E85's very high octane rating would have also been widely publicized, instead I have seen an octane rating on exactly one E85 pump ever. Now that we very well know ethanol raises octane, it still isn't a factor. It seems any time there is discussion outside of the racing community (where it has some big fans) about actually using ethanol to boost octane and moving beyond the 1970s post-leaded-gas malaise-era 87 octane standard, you get all of the "it screwed up my chainsaw I hadn't used for four years" or "you are just making evil Monsanto rich", "you are starving kids in Zimbabwe," and the other usual responses. And now we are stuck with DI setups and their significant drawbacks in gasoline engines in order to try to work around running a heavily-turbocharged engine with double-digit compression ratios on the same swill that barely ran engines with maybe an 8:1 compression ratio in the '70s.

 

[MossRoad]

Coincidentally, I'm watching an Engine Power show where they built a small block chevy and ran it on gas, then ran it on E85. It makes about 25% more power on E85.

 

[5030]

Which has NOTHING to do with a chainsaw...

 

[MossRoad]

 

[5030]

If that was my cat, I'd eliminate it.

 

[arto98607]

Switching to Diesel chainsaw will solve all these gasoline problems some of you are having.....

 

[5030]

Switching to Diesel chainsaw will solve all these gasoline problems some of you are having.....

Only ever seen one and it was a Chinese saw.