2 stroke longevity - how many hours

80 & 100 are recommended by Amsoil right on the bottle - they leave it up to you to decide. They stake their reputation on it. Some people aren't comfortable with either and mix at 50:1 - that's fine - it's your money as I said. If you want to use double the necessary oil, totally fine.

Same with their 4-stroke engine oils and their 25k recommended changes. That's a different ballgame in the 21st century, so I won't get into that here ( long and short, I'd do that on my '86 Grand Marquis, but no chance in hell anything built after 1994).

66, as I mentioned way back in this thread, was used by a paramotor instructor from LA (NOT L.A.) for years on MANY different units in a training environment - in other words, he's tested, tested, and retested that with zero I'll effects. If it can handle the heat down there, I figure that's good enough up here for me in MA.

Smithsonite said:

80 & 100 are recommended by Amsoil right on the bottle - they leave it up to you to decide. They stake their reputation on it. Some people aren't comfortable with either and mix at 50:1 - that's fine - it's your money as I said. If you want to use double the necessary oil, totally fine.

Same with their 4-stroke engine oils and their 25k recommended changes. That's a different ballgame in the 21st century, so I won't get into that here ( long and short, I'd do that on my '86 Grand Marquis, but no chance in hell anything built after 1994).

66, as I mentioned way back in this thread, was used by a paramotor instructor from LA (NOT L.A.) for years on MANY different units in a training environment - in other words, he's tested, tested, and retested that with zero I'll effects. If it can handle the heat down there, I figure that's good enough up here for me in MA.

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I have seen Amsoil at trade shows over the years. Even had a guy that came by my house about 25 years ago selling Amsoil. I realize it is a “premium “ product. I wonder what percentage of the 2-stroke oil market Amsoil has? I bet it isn’t much. I wouldn’t mix gold at 100:1.

GearHead36 said:

OK, but that RD weighs (according to Wikipedia) 342lbs. A truck weighs over 10X that. Although I have to say, that must be a VERY well tuned RD. My 4-stroke bikes never got mileage that good.

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Consistently 50+ mpg on a Yamaha FJR1300a

Douglas Lee said:

So . . . are you saying with an older (25 + years old ) chain saw, it's ok to run it with a 100:1
fuel mixture verses the 16:1 suggested by the manufacturer?
Thanks,
Doug Lee
*

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Are the bearings plain or ball? Ball bearings were introduced sometime in the 1920s to 1930s...you have to do a patent search to see who claimed to be first or at least had the idea. Needle bearings came along later in the 1930s and40s.

My guess is that anyone recommending 16:1 was specifying plain 30wt motor oil for whatever reason. Could have been castor but kinda doubt it. Lubrication technologies have moved so far from their beginnings. Most think that if a little is good a whole lot of oil is better. Ball bearings at high speeds will skid in the race if given too much lubrication, the hydrodynamic wedge prevents them from turning and that is dependent on Saybolt range of the lubricant. But that's usually a racing problem unrelated to your question.

If the saw has ball and needle bearings, yeah, I'd run an oil that is engineered for 100:1 at maybe 80:1 if you're nervous about 100:1. Scary, isn't it.

Tiger Small Engine said:

I have seen Amsoil at trade shows over the years. Even had a guy that came by my house about 25 years ago selling Amsoil. I realize it is a “premium “ product. I wonder what percentage of the 2-stroke oil market Amsoil has? I bet it isn’t much. I wouldn’t mix gold at 100:1.

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You mean "premium" as in price? Well, if you're using less per gallon of gas, but you'd need 2x+ as much of the other stuff....is the price per gallon of gas the same or less.

And generally price is not the driver. Do the rings stay free? Do you have to decarbon routinely? Do the plug(s) routinely foul? Is the exhaust port staying free of carbon? If the answer is no.....

Had an Ultralight with a 50hp Hirth 2704 running 100:1. Doing that is serious stuff. It's not just being inconvenienced by oil caused problems, it's landing out somewhere where there isn't a landing strip, or road, or clearing. At 400+ hours there was zero carbon on the pistons, none in the exhaust ports, the plugs were still the originals and they looked like a four stroke plug...nice and tan at the porcelain tip running to just a bit darker down into the shell.

Scarey, ain't it.