Oil ratio for a Scott Atwater 16

[fisherman6]

Maybe I’ll start testing this motor with something like 70:1 or 80:1 mix when I start. I’ll see how daring I get. That’s really stretching it for a guy that has historically never tried to scrimp on oil in my premix. Especially in a motor that isn’t FULL needle bearings. 😯
-Ben

OldJohnnyRude on YouTube

[1946zephyr]

Well, in the 30+ years I have ran engines, I found that replacing a fouled plug, is much easier (and cost effective), than it is to change a scored piston. Anyone disagree with that? 😀
Sure, the excess oil may or may not add benefit, however, more oil will pass through the moving parts while they spin.
I don’t hold 100 percent credibility to factory recemendations anyhow. Some have not been correct. You have to remember that when the engineers design these engines, they are going by their best judgement and the real results of their "judgement" won’t show up till years later. As it has been pointed out, OMC changed their oil recemendations in around 1964 or 65. I believe in this case, the Lightwins may have been victimized by this change, because they still were a 100% friction motor! So, I don’t hold factory recemendations gospel.
To add what I said about chainsaws and dirt bikes earlier, these machines spend a very large percentage at wide open throttle unlike outboards which usually only are at wide open throttle going to and from the fishing hole. Then they spend a large amount of time trolling. Well, dirt bikes, chainsaws and all other 2 stroke engines very seldom ever idle or troll.

[fisherman6]

I completely agree that from a strictly monetary cost perspective I would buy the oil and spark plugs and run the mix on the heavy side. That’s what I have always done in the past. To me that isn’t goal in the attempt to reduce the amount of oil.

At the risk of sounding like a tree hugger (which anyone who knows me will tell you I’m not) the main goal is to reduce the emissions / pollution generated in an attempt to prolong the ability to run these motors in as many places and for as long as possible. I do not want to have my motors regulated out of service. If the pollution can be reduced without sacrificing the engine life, then why not. For me (and I believe I speak for most interested in reducing the amount of oil, forgive me if I’m wrong) it isn’t about saving a couple bucks because I am getting away with something. I want to be able to keep running these motors on the lakes and not have my hobby regulated out of existence.
-Ben

OldJohnnyRude on YouTube

[1946zephyr]

Then you should by a new 4 stroke. Problem solved 😀

Unfortunately our hobbies will be down to sawhorse queens that go in the barrel a couple times a year 🙁

[fisherman6]

That’s what I want to avoid for as long as possible. If I wanted to buy a new 4 stroke, I’d do that, but that’s not what I want. I have too much fun with my 2 strokes. I’m not here to stir the pot, just want to do what I can to preserve the hobby. If I can do my part by reducing oil and using a biodegradable alternative to dino oil, if nothing else maybe I feel better.
-Ben

OldJohnnyRude on YouTube

[1946zephyr]

I heard that Amsoil may allow you to go lighter on the mix.

[creekrunner]

……like an old cracked record…..oil ratio’s …on and on and on……newer twc3 oil’s are so much better than the offerings through the ’60’s.
use the newer product and mix them to smoke a little….a little blue smoke on the water is aesthetically pleasing in my book. Doubters and
experimental engineers should switch to 3-in 1 oil and see where that takes them………it may now even be synthetic ………

[jcrigan]

Not trying to change the subject, but isn’t the oils other purpose is to aid in the transfer of heat? Or was that more of a concern for the older cast iron motors without the rubber impellers.

[PugetSoundBoater]

We are already aware that friction causes heat. Lubricating oil reduces friction substantially and helps dissapate and "transfer" heat, which in turn reduces wear on moving metal to metal contact surfaces.
Oil is a good thing .
In the case of our 2 strokes…oil in a reasonable quantity
What’s a reasonable amount,quantity and ratio? That’s what this topic is about.

"Some people want to know how a watch works, others just want to know what time it is"
Robbie Robertson

[jeff-register]

Guys,
I believe the factory ratio is there for reasons unknown to me. I too enjoy my collection as well & want to keep them running. I use good OMC or Merc oil at the ratio shown from the builder as well.
I’m safe now & if something goes bad it’s my fault not listening to what the motor is speaking to me.

[Author]

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