oil mix ratio for "High Performance"

**outlaw 10.5** · 09-08-2016, 08:07 PM

Guys,
I was looking through my OMC manual and noticed it said " for High Performance Use" without VRO , mix oil ratio to 25:1.
Has anyone else done this ? What do you High Performance OMC guys do? I have a pair of 2000 225 HO carb motors, Monty heads with about 130 # compression and 93 octane fuel.

Thanks
Tim

**jwall116** · 09-09-2016, 09:11 AM

I was wondering that myself. I have a bone stock OMC 130 Looper, and pre-mix at 50:1

**FMP** · 09-09-2016, 09:43 AM

Somewhere in the wealth of information on this site is a test that shows you make more power with a bit more oil. If you run it hard and spin it you might as well be covered with a bit more film to reduce the friction and protect. Its an old test but still applies even with today's " better oils" , so why take the chance. I looked at a neighbours late model 15 Johnson two stroke the other day and noticed the sticker 100:1 , I said why?

**outlaw 10.5** · 09-09-2016, 03:08 PM

No one can tell me what they mix for High Performance use. I know it may be mixed opinions but someone could chime in. I'm just curious because I have always mixed 50:1 but would mix 40:1 or 32:1 if that would be better for longevity.

**FMP** · 09-09-2016, 03:49 PM

So if its continuous 6000+ use 40:1 at least and 32:1 if you're really turning it and want to be safe.

**Robby321** · 09-09-2016, 04:44 PM

Originally Posted by FMP

So if its continuous 6000+ use 40:1 at least and 32:1 if you're really turning it and want to be safe.

I totally agree..

**flabum1017** · 09-09-2016, 05:22 PM

Normal use is fine with whatever the manufacturer suggests..... A lot of the Lemmonrudes went to 100:1 in the eighties. Personally, I like 50:1 for fish/stock motors and 40:1 to 32:1 for hard running, high rpm motors...... I'd rather replace plugs than pistons and bearings

**FORBESAUTO** · 09-09-2016, 05:45 PM

With above post. I run 40:1 up to 6500 and 32:1 above that. 50: 1 stock. I experience motors seem to make more power with richer oil mixtures. But be aware that the richer oil mixture can lean it a tad and may need to richin up slightly to compensate.

**Mark75H** · 09-09-2016, 06:16 PM

Was at a race about 5 years ago pitted next to Fred Hauenstein (former high up engineer at both Merc and OMC ... and long time second generation boat racer)

Watched him mix his own oil ... 25:1

**FMP** · 09-09-2016, 06:23 PM

Oil her up

**outlaw 10.5** · 09-09-2016, 06:26 PM

Thanks for the replies guys, I just mixed it 40:1 , motors turn 6300 with current set up and don't run there that often , mostly cruise about 4500 or so.

**olboatman** · 09-09-2016, 07:11 PM

I also agree that the higher you spin a two-stroke the more oil needed. I do not think that 100 to 1 is exceptable over 1000 rpm!!! JMO Gary

**flabum1017** · 09-09-2016, 07:44 PM

Originally Posted by olboatman

I also agree that the higher you spin a two-stroke the more oil needed. I do not think that 100 to 1 is exceptable over 1000 rpm!!! JMO Gary

Oil has vastly improved from the old days Oldboatman

.

**Umassot50** · 09-09-2016, 08:01 PM

The only time "newer better" oils are any better is when you get down to the bare minimum acceptable oil level for your engine. The slightly better film strength and higher flash point will protect better when your at the absolute minimum oil level. Add a little more oil and it's a wash. More oil is better for more power and protects engines from wear. Two strokes love oil. Dont deprive them.