Thoughts on Opti2 two stroke oil?
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A long way from the OMC oue quart to a six gallon outboard tank requirement.
Used it for 5 years on my 1992 Yamaha WR250R. I mixed at 75:1, I did not have the guts to go 100:1 (what Opti recommended). Flawless oil, top end showed no wear after 5 years of medium duty Enduro use. Minimal smoke, excellent oil.
Again, there really is no magic for 2 stroke oil ratio's.
32 to 1 provides all the protection possible, with the exception of very highly tuned race engines, such as 55HP, 125cc Kart engines.
50 to 1 is good enough for low stress engines. But, will result in slightly more wear for high performance engines.
100 to 1, regardless of oil type, results in significantly more wear.
Some oils that recommend lean ratio's, are either higher viscosity or contain no mixing agents or thinners (often a very small component of the oil, by percentage) . This does not mean you will achieve equal engine life at 100 to 1 with these "magic" oils. That "theory" has been soundly debunked.
And, 16 to 1 provides the most HP, jetting and other factors being equal. (8 to 1 may make a touch more power, but it's difficult to deal with)
32 to 1 provides all the protection possible, with the exception of very highly tuned race engines, such as 55HP, 125cc Kart engines.
50 to 1 is good enough for low stress engines. But, will result in slightly more wear for high performance engines.
100 to 1, regardless of oil type, results in significantly more wear.
Some oils that recommend lean ratio's, are either higher viscosity or contain no mixing agents or thinners (often a very small component of the oil, by percentage) . This does not mean you will achieve equal engine life at 100 to 1 with these "magic" oils. That "theory" has been soundly debunked.
And, 16 to 1 provides the most HP, jetting and other factors being equal. (8 to 1 may make a touch more power, but it's difficult to deal with)
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Thanks Cujet, i'm wondered about all these different ratios. I've always been afraid to run 100:1 in my weedeater and chainsaws, i go with 40:1. And i am definitely using 32:1 in the lawn boy after reading your posts and others on the bushing vs needle bearings.
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I ran neooil @100:1 (recomended mix) back in the 80's and could not keep the engine from seizing.its been 30 yrs and I'm still skeptical.
Actually cujet, from all the dyno tests and studies I've read the magic power ratio was 18:1, just a hair less oil but whos counting...
I run all my OPE at the suggested ratio of Amsoil's sabre mix, I think its 75:1 but my kart racing engines and RM250 get 32:1 no matter what oil is used.
I run all my OPE at the suggested ratio of Amsoil's sabre mix, I think its 75:1 but my kart racing engines and RM250 get 32:1 no matter what oil is used.
Originally Posted By: racin4ds
Actually cujet, from all the dyno tests and studies I've read the magic power ratio was 18:1, just a hair less oil but whos counting...
Hahahahahha, too funny! I'm not at all certain any testing I've been involved with could tell the difference.
It was only a matter of a couple of percent power increase going from 50 to 1, down to 16 to 1.
Actually cujet, from all the dyno tests and studies I've read the magic power ratio was 18:1, just a hair less oil but whos counting...
Hahahahahha, too funny! I'm not at all certain any testing I've been involved with could tell the difference.
It was only a matter of a couple of percent power increase going from 50 to 1, down to 16 to 1.
How would a richer oil mixture like 16:1 compared to a 50:1 increase hp? Not doubting, just unsure of how that works.
I run a 50:1 in all my equipment, and with my experience in outdoor power equipment repair, a richer oil mixture leads to more carbon build up.
I recently had an ice auger come in with a Tecumseh 2 stroke on it. The machine had very little compression. The piston and cylinder were scored from carbon build up, and the guy said he ran a mixture that had too much oil. There was a ton of carbon build up around the exhaust port.
I run a 50:1 in all my equipment, and with my experience in outdoor power equipment repair, a richer oil mixture leads to more carbon build up.
I recently had an ice auger come in with a Tecumseh 2 stroke on it. The machine had very little compression. The piston and cylinder were scored from carbon build up, and the guy said he ran a mixture that had too much oil. There was a ton of carbon build up around the exhaust port.
More oil seals the rings better.
18.1 is generally the hp peak. Anything more or less looses hp. Not that it's a bunch of hp loss, unless you are at something silly like 6.1.
I doubt your cylinder was scored from carbon. At least not deep enough to cause compression loss. Sounds more like worn out rings. 2stroke engines need piston/ring maintenance way way more than 4strokes.
18.1 is generally the hp peak. Anything more or less looses hp. Not that it's a bunch of hp loss, unless you are at something silly like 6.1.
I doubt your cylinder was scored from carbon. At least not deep enough to cause compression loss. Sounds more like worn out rings. 2stroke engines need piston/ring maintenance way way more than 4strokes.
Originally Posted By: Srt20
More oil seals the rings better.
18.1 is generally the hp peak. Anything more or less looses hp. Not that it's a bunch of hp loss, unless you are at something silly like 6.1.
I doubt your cylinder was scored from carbon. At least not deep enough to cause compression loss. Sounds more like worn out rings. 2stroke engines need piston/ring maintenance way way more than 4strokes.
Actually, we found even more power at 8 to 1, but idle was difficult. On a boat, that's a problem.
More oil seals the rings better.
18.1 is generally the hp peak. Anything more or less looses hp. Not that it's a bunch of hp loss, unless you are at something silly like 6.1.
I doubt your cylinder was scored from carbon. At least not deep enough to cause compression loss. Sounds more like worn out rings. 2stroke engines need piston/ring maintenance way way more than 4strokes.
Actually, we found even more power at 8 to 1, but idle was difficult. On a boat, that's a problem.
My bag is long term had great results with the older Shindaiwa can't be beat long term hours.
Basic maintenance after so many hours is to tear it down and clean it. Either way you look at it the 2 stroke is a dirty application go with manufacture recommended. Never used synthetic oil(commerically) not saying synthetic oil would make a difference(maybe not being bias)BUT the difference was proper cleaning and fuel maintenance practice was the key. Keeping the 2 stroke running efficient. Also spark plug can HAVE a play. In hotter running engine full wot in long hours 2-3 gallon daily can take a beating....a spark plug that gets out of range can DECREASE the life of an engine 25-40%. Use a proper spark plugs Shindaiwa recommends the NGK for their newer hotter running engine, Champion do offer a high temp spark plug for small engines. I've seen it happen when a spark plug cause damage shorten the life an engine....the proper plug should had been a NGK or a high temp spark plug but a lesser plug was used and this was from the older Shindaiwa models....
PS is from my experience
Basic maintenance after so many hours is to tear it down and clean it. Either way you look at it the 2 stroke is a dirty application go with manufacture recommended. Never used synthetic oil(commerically) not saying synthetic oil would make a difference(maybe not being bias)BUT the difference was proper cleaning and fuel maintenance practice was the key. Keeping the 2 stroke running efficient. Also spark plug can HAVE a play. In hotter running engine full wot in long hours 2-3 gallon daily can take a beating....a spark plug that gets out of range can DECREASE the life of an engine 25-40%. Use a proper spark plugs Shindaiwa recommends the NGK for their newer hotter running engine, Champion do offer a high temp spark plug for small engines. I've seen it happen when a spark plug cause damage shorten the life an engine....the proper plug should had been a NGK or a high temp spark plug but a lesser plug was used and this was from the older Shindaiwa models....
PS is from my experience
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