Oil/fuel mixtures and Carb set

[jtower3941]

Have a Y102. Does a 32:1 oil/gas mixture compaired to a 50:1 oil/gas mixture change the carb setting as to rich and lean??? Example 38 klicks carb setting and 32:1 change to 50:1 carb set at 34 klicks, richer setting.

[pops67g]

Oil is cheaper than parts!!!

DON'T skimp on oil in a race motor. Forget this 32 and 50 to 1 stuff. Two strokes run stronger and longer with more oil to carry excess heat away and provide a better ring seal. I run my 4-cyl. Mercs (stock and mod) at 8:1 and they live long and prosper. Spending an extra $50 on oil for a season sure beats laying out $1100+ for a new crank (if you can find one).

[David_L6]

DON'T skimp on oil in a race motor. Spending an extra $50 on oil for a season sure beats laying out $1100+ for a new crank.

Very good advice there.

[mercguy]

DON'T skimp on oil in a race motor. Forget this 32 and 50 to 1 stuff. Two strokes run stronger and longer with more oil to carry excess heat away and provide a better ring seal. I run my 4-cyl. Mercs (stock and mod) at 8:1 and they live long and prosper. Spending an extra $50 on oil for a season sure beats laying out $1100+ for a new crank (if you can find one).

more oil in Yamatos DOES NOT make them stronger and is a waste of money!!!! Mercs run better with a LOT of oil, due to the labrynth type sealing surfaces on the reed cages.........

all that extra oil in Yamatos just gums up the exhaust housing and exhaust chamber........................32:1 or 40:1 is just fine................

no significant adjustment is needed on the high speed needle, as that is just an air/fuel adjustment..........

BUT, spend your money a a GOOD 2cycle oil!!

[ryan_4z]

We always run 24:1 in the Yamato with regular 2 stroke oil; 50:1 with synthetic Amsoil.

[sam]

The change between 32:1 and 50:1 is not enough to make a fuel mixture change ... 50:1 is 2% oil, 32:1 is 3% oil ... only a 1% change if the oil has no fuel content ... but it does burn and contributes some fuel content.

[David_L6]

I don't remember for sure what we ran when we were running Yamatos. It was either 20:1 or 24:1 with synthetic (Klotz R50). Whatever Dudley told me to run...........

The "classic" mixture for the old Hot Rods (and 2 cyl. Mercs) is 8:1 - 1 pint oil per gallon of gas. I've run that much oil in my B Mercs but not in my C,D,E Mercs.

I run 3 pints to 5 gallons in my 4 cylinder Mercs. I ran 3 pints to 4 gallons for years. Didn't change anything when I switched from 3 to 4 to 3 to 5.

Run "good" oil and "good" gas and you won't have a problem as long as you don't run too little oil. I'd say too little is less than 24:1 but that's me. I tend to agree with pops67g - oil is cheaper (and easier to find) than parts.

Keep asking questions - fuel/oil ratio isn't a speed secret. Run what the guys you are racing with run (mercguy runs Yamatos). I can (and did) tell you what I am running in my motors but I don't run Yamatos.....

Avoid gasohol. If you have to pay extra for gas without alcohol in it the extra cost up front will be cheaper in the long run. Don't worry about high octane gas for a Yamato. It's not needed.

[ZUL8TR]

Oil Brand

more oil in Yamatos DOES NOT make them stronger and is a waste of money!!!! Mercs run better with a LOT of oil, due to the labrynth type sealing surfaces on the reed cages.........

all that extra oil in Yamatos just gums up the exhaust housing and exhaust chamber........................32:1 or 40:1 is just fine................

no significant adjustment is needed on the high speed needle, as that is just an air/fuel adjustment..........

BUT, spend your money a a GOOD 2cycle oil!!

What brand 2 cycle do you use?

[QUINAULTRACING]

Good Oil

Redline

[mercguy]

[QUOTE=ZUL8TR;130847]What brand 2 cycle do you use?[/QUOT

Amsoil Dominator!

[JBM]

Amsoil

I stuck a piston in my 102 last weekend (from lack of cooling) running Amsoil Dominator. When I tore the engine apart I found a light oil coating on everything inside. Cylinder cleaned up with a little muriatic acid and I think I can sand the scuff marks off of the piston. As far as jetting, It would make sense that less oil would flow faster, but that small change of ratio? (engineers jump in)