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View Full Version : " what oil/fuel ratio you like to use ??"



dart
10-24-2012, 01:26 AM
hi guys
i have been a fan of " amsoil "full synthetic oil once engine is always run in on non synthetic oil.
any way i have used dominator on air cooled non marine two strokes.
and currently use Saber outboard amsloil synthetic oil on my 50 hp mercury(tohatsu).
generally i run the oil/fuel ratio at 50:1 with mods i have done.
the plugs run a nice dry coffee color.
alot of guys reackon with all the mods they run,they like to use 40:1 ratio or even more oil.
i have heard that a little more oil can increase hp ??
and i suppose gives a bit more lubrication,but the amsoil seems such thick good quality oil that at 50:1 is good enough of a oil/fuel ratio,your thoughts please ?
also i came across another amsoil sytnthetic oil called " hp marine " oil,is this any good ??
have you used it before?
im still waiting on amsoil tech dep to get back to me r.e there oils!!
thanks
glen

dart
10-24-2012, 12:13 PM
how come no replies ???,doesnt any one use two stroke oil????:rolleyes:

Bunker Hill
10-24-2012, 03:22 PM
Here is a reply:
Back in the day, 1960's through 1980's, before synthetic oils and before looper engines, in our race engines, KG 4's, KG 7's, 9's Mk 30H and Mk 55h's we ran 2 quarts to five gallons. This was over kill but in a cross flow, that worked pretty well. I today's world, in loopers, I always ran appx. 32 : 1, it seemed like a good number. As far as more horsepower, I have two thoughts:
1) Synthetic burns more completely and may add more power, in loopers only. the theory being that synthetic creates so much lubricity, that rings cant set or seal properly
2) Crossflow engines were designed back when petroleum oils were the only lubrications available and some of the compression in a crossflow comes from the non burnt oil so using petroleum oils can, i believe, raise compression.

On a few side notes...
I would not attempt to "Break in an engine" using synthetic oil, I believe it lubricates so well, that rings may not "Set" properly
and... keep in mind a lower fuel:oil ratio, lower being 10:1 rather than higher 50:1, will in effect, lean the engine out.
I think you are doing the right thing however, the sparkplugs are the window to an engine's happiness

-Bunker

Binger
10-24-2012, 05:19 PM
Here is a reply:
Back in the day, 1960's through 1980's, before synthetic oils and before looper engines, in our race engines, KG 4's, KG 7's, 9's Mk 30H and Mk 55h's we ran 2 quarts to five gallons. This was over kill but in a cross flow, that worked pretty well. I today's world, in loopers, I always ran appx. 32 : 1, it seemed like a good number. As far as more horsepower, I have two thoughts:
1) Synthetic burns more completely and may add more power, in loopers only. the theory being that synthetic creates so much lubricity, that rings cant set or seal properly
2) Crossflow engines were designed back when petroleum oils were the only lubrications available and some of the compression in a crossflow comes from the non burnt oil so using petroleum oils can, i believe, raise compression.

On a few side notes...
I would not attempt to "Break in an engine" using synthetic oil, I believe it lubricates so well, that rings may not "Set" properly
and... keep in mind a lower fuel:oil ratio, lower being 10:1 rather than higher 50:1, will in effect, lean the engine out.
I think you are doing the right thing however, the sparkplugs are the window to an engine's happiness

-Bunker

Actually synthetic oil's don't burn completely as semi synthetic or mineral oils do.

Binger
10-24-2012, 05:22 PM
Lucas carries 2 stroke oil and they sure are trying to support boat racing with there new drag track they built , remember support those who support you :) http://www.lucasoil.com/products/display_products_overviews.sd?iid=13&catid=6

Bunker Hill
10-24-2012, 08:48 PM
Actually synthetic oil's don't burn completely as semi synthetic or mineral oils do.

I was refering to pure petroleum oils, thanks for the clarification
Bunker

dart
10-25-2012, 04:13 AM
hi guys
thanks for your replies and info!!
i brought some "redline " race synthetic oil today!!
looks nice thin quality oil
will try it at 50:1 ratio.
quite expensive,cost me $26 aud for 473 ml.
i reackon it may be quite good perf oil,such as protection/lubrication,possble slight more hp,less wear,less gumming up e.c.t
cheers
glen

Bunker Hill
10-25-2012, 12:17 PM
Red Line is a very popular choice, I have only heard good things about it!
Good Luck!

dart
10-25-2012, 12:38 PM
Red Line is a very popular choice, I have only heard good things about it!
Good Luck!

yep im looking fwd to trying it out!!
cheers
glen

Yellowjacket
10-25-2012, 01:13 PM
Any thoughts of how much oil to run should be coupled to what kind of oil it is and how you are running your motor.

You can, to some extent, make up for some lack of lubricity by using more oil, but using more oil comes with issues of plug fouling and carbon buildup, so there is no free lunch.

Here is a link to a thread where a several different oils were discussed, as well as the rating of the oil relative to the needs of an outboard. And remember that a outboard that is run at full throttle and higher RPM's than stock has requirements that are significantly different than the guy who is running at low speed and trolling for fish.

http://www.boatracingfacts.com/forums/showthread.php?13077-What-2-stroke-oil-yall-runnin

If you aren't running higher rpms's than stock, and you aren't running at wide open throttle all the time there's a lot of options and most any oil that is rated as TCW-3 is fine. I'm sure some are better than others, but for normal use it really isn't going to matter all that much. After taking apart a few high time outboards I'd be looking for one that has the highest detergent capability, since these things are downright nasty in terms of carbon buildup.

If you are running the engine hard you need to look for oils that are rated as JASO FD AND TCW-3 since these give you the best of both worlds in terms of high heat and lubricity protection and the ability to work at low temperatures like you find in an outboard.