narisseproe
16.05.2021 20:44:04
One pint TCW-3 outboard oil to six gallons of 87 octane. more
See full version: 90hp 2 stroke oil/fuel ratio
One pint TCW-3 outboard oil to six gallons of 87 octane. more
Re: 90hp 2 stroke oil/fuel ratio
Thanks DJ, but now I'm confused. Since I posted the question I found my original manual and paperwork. The manual only says 50:1 during breakin or after a long storage. My salesperson wrote down 25:1. I've been using a measuring bottle at 24:1 for as long as I can remember. Could that be why I have so much soot in the prop exhaust? Otherwise the engine has been running great. Carb's were cleaned two months ago even though they were practically spotless.
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Re: 1987 8 HP Yamaha Oil Mixture ?
I called an outbourd repair shop and they said 50 to 1 but they also said that for the one that I knew for a fact was 100 to 1. The guy told me that all two stroke motors used 50 to 1. Just shows you can't always trust the so-called experts.
Re: 1987 8 HP Yamaha Oil Mixture ? here
Vintage snowmobiles and motorcycles from that era suggested premix ratios ranging from 20:1 to 40:1. Conventional 2-stroke oils from the 70’s would have a fraction of the film strength of today’s sophisticated synthetic 2-stroke oils. Anyone who rode snowmobiles back in those days remembers the clouds of smoky exhaust. A larger volume of oil had to added to the fuel to provide adequate engine protection.
When using a modern 2-cycle oil, go with the ratio suggested on the oil bottle label. It will work just fine. When ever changing to a different 2-stroke oil, it’s a good idea to do a spark plug reading.
AMSOIL Interceptor Synthetic 2-Stroke Oil is the absolute cream of the crop for the very latest high-tech snowmobiles. It also highly effective as a premix in older engines. Interceptor offers a sophisticated synthetic base oil and a high detergent content for ultra-clean combustion and incredible deposit-fighting ability. Interceptor is the ultimate 2-stroke oil for maximum performance and wear control. here
Personally, and I think other really intelligent people agree that it makes sense to mix a gallon of gas at say 20:1, 32:1 and 40:1 and test it and see which blend makes you bike run better. It’s an easy way to validate which way targets your style of riding and allows for easy changes when you head up to higher elevation and don’t want to rejet. One thing to bring up is that at higher elevations and temps that summer seems to bring, you may not be able to get a small enough pilot jet in the 300 to run well at 60:1, since the pilot jets are close to the end of the available range. here
I just bought a relatively pristine 2015 KTM 300 XCW from a dealer. As I left the service dept after prep, the service manager told me that it had gas with an oil ratio of 32:1. He said to switch to 60:1. Thing is, it runs pretty good with the 32:1, and knowing enough to know that 60:1 will make it run quite a bit richer (less oil = more gas to the same amount of incoming air = richer) and the fact we are going into summer, would you do this?
Next you have the slide and needle, with the clip in the set of grooves. Moving the clip up or down is the most common change people make, making the bike run richer or leaner from about 1/4 throttle to 3/4 throttle. Moving the clip up makes the bike leaner and down makes it richer. [links]
In the world of two stroke jetting, other than the actual brass jets themselves, there are three other factors, outside of deteriorating engine condition, that contribute to the overall jetting of the bike. And by jetting, we mean if the bike is running rich or lean. The three factors are air temperature; elevation and the ratio of fuel to oil you choose to run. more
In a two-stroke engine, there is actually primary and secondary compression. In the world of jetting, I consider the fuel – oil ratio the primary jetting and the jets secondary. This is because the fuel – oil ratio fed to the carb, not only affects all jetting ranges, but also determines it first, before it gets to the jets. A ratio of 20:1, which is 6 oz of oil in a gallon of gas, will make the bike run noticeably leaner than a ratio of 40:1, which is 4 oz of oil to a gallon. here