40:1 PreMix 2001 Johnson 90 HP 2 stroke

[spybot]

On a wee side note. I had a OMC 85 that when i got it i was told to run 25/1 mix.
I used it like this for a summer. The following summer i got some fuel from my mate ( i had used all mine and it was a 1 hr round trip for more, he was going home so lent me his spare gas tank) I put it in my motor and she could hardly get on plane no power at all. She revved great at the slip but not under load. After a bit of time checking everything nothing had changed bar the fuel. I called my mate and asked what mix he had used in the tank of gas i got from him. Just normal he said 50/1 Bang ! there was my problem right there. I was running to weak a mix.) I added more two stroke tried her again. She jumped out of the hole back to her old self.

So in my case (Which after a tear down i found shot crank seals) my motor need the viscosity of the richer mix to somehow block/cover ???? The leaking parts of my motor.

Cheers Andy

 

[Chris1956]

Some really crazy stuff on this thread......

 

[racerone]

All entertaining.----Had someone say ----" why should I use good oil. the motor just burns it ? "--that was many years ago.

 

[thumbnut]

Whats entertaining is go to another outboard forum and you will get a different point of view about mix ratio..this forum tends to be conservative and people stick to manufactures recommended mix...50/1 is not all about technical reasons for this ratio.

 

[flyingscott]

How is 50-1 not all about technical reasons. There is literally a technical bulletin from OMC to run their motors at 50-1.

 

[racerone]

What is technical about a 50:1 ratio.------They went from 24:1 to 50:1 overnight.----37:1 from laboratory work I can understand.----50:1 was a " board room " decision.---Motors will last an acceptable number of hrs with less smoke at that ratio.----That is what the public wanted and that is what they got !

 

[thumbnut]

In reality mix ratio is all about compromises. Corporate politics, stock holders, duty cycle and so forth are factored in. Stock holders don';t want the product to last forever...there is a sweet spot with regards to life span..last too long and sales suffer...look at our glut of used cars...they are lasting too long. Not long enough and rep suffers cutting into sales. Too much smoke and one thinks the product is substandard.

One manufacture recommends 50/1 and another says 32/1 is best. I bet more than half would say the 32/1 motor would be seen as inferior...when actually the 32/1 manufacture folx are just thinking more in our favor.

Read the lab study Gorden Jennings...did on mix ratio.

Go to an outboard forum where they spend hours on their motors and see what they run for ratio.

Go to a snowmobile forum and see what they run.

Go to a chain saw forum and see what they run.

Its all a compromise..



Dammm racerone..ya bet me to it...

 

[flyingscott]

Ok snowmobiles and chainsaws are not the same. I do not know-how many times Racerone has said the 22 did OMCs are wonderful motors. That they will outlast the newer motors but how can that be at 50-1. they should all be in the scrap heap from being worn out. Answer me why my 75 is still running strong at 53 yrs young. People run a higher ratio of oil for piece of mind not for the motor or any perceived benefits you may get from it. The fact people won't let the facts get in their way amuses me. This is 2018 people oil ratios from the 50s should stay with the 50s motors. Anything after 1964 will be fine on a 50-1 ratio as proven by all the 1964 motors still running today.

 

[thumbnut]

You

Sorry..wasn't trying to be snarky...

Oh...I did go on those sites to be better ejumacated....prolly didn't help!

 

[flyingscott]

Sorry..wasn't trying to be snarky...

Oh...I did go on those sites to be better ejumacated....prolly didn't help!

I edited that

 

[thumbnut]

Ok snowmobiles and chainsaws are not the same. I do not know-how many times Racerone has said the 22 did OMCs are wonderful motors. That they will outlast the newer motors but how can that be at 50-1. they should all be in the scrap heap from being worn out. Answer me why my 75 is still running strong at 53 yrs young. People run a higher ratio of oil for piece of mind not for the motor or any perceived benefits you may get from it. The fact people won't let the facts get in their way amuses me. This is 2018 people oil ratios from the 50s should stay with the 50s motors. Anything after 1964 will be fine on a 50-1 ratio as proven by all the 1964 motors still running today.

I didn't read where one said 50/1 won't get the job done..50/1 is okay..

Most over pour and under fill unless ocd is in effect anyway as another said...

Also many of those older carbed 2 strokes run fat anyway so it usually takes quite a lean out to injure.

 

[stewtn]

I'm glad I've got options!!

 

[Sea Rider]

Have used several brand of oil, some can treat 12 gallons per one 1/4 bottle, others 13 gallons per bottle if like adding one measurement of oil at a time per gallon. I use a 80 mil lab pipette of oil for every 1 gallon poured into tank, my fuel/oil ratios are always 100% spot on.

A 2 strokes OB whether used at 40:1 or 50:1 will foul plugs prematurely when trolling at idle or fast idle speed for long time periods due to spark plugs are not reaching its self cleaning temp which is over 450 Cº. That's what a wot run as stealing the combo is mandatory for plugs to clean themselves when going back to Terra Firme..

Happy Boating

 

[Chris1956]

Well everyone is entitled to his/her opinion. I would call most of this thread "alternative facts", as they have no relationship to actual facts.....

 

[jimmbo]

Opinions are like Hemorrhoids... and we know what has them

 

[Sea Rider]

Actual facts is the fuel/oil ratio that each outboard manufacturer recommends to go per Owner's Manual written literature. Adding more of less 2 strokes oil ratio is entirely y up to each boater mood.

Happy Boating