RM125 02 Rm 125 low power

Of course, the basics of rich/lean mean fuel/air not gas/oil. The fuel has oil in it, but is still fuel. Reducing the ratio of oil/gas only reduces the amount of lubrication. You engine needs lubrication. Less oil will make it run hotter, but not leaner. The rich lean condition is always referring to the fuel. Rich= too much fuel Lean= too little fuel.
Actually reducing the amount of oil leaves more fuel to burn, thus a slightly richer air fuel mixture.
 
Yeah, I'm kinda lost at this point. I also need it to stop running so rich. Started with 32:1 then 38:1 then 40:1 all same result.

If you are changing the amount of oil in the gas that would be wrong. You tune it with the carburetor not the oil mixture. Hint: factory spec is 30:1 I would run it at 28:1 and if I were 16 again 20:1.
Still 28:1 is optimum for high rev MX.
 
Actually reducing the amount of oil leaves more fuel to burn, thus a slightly richer air fuel mixture.
Negative sir. Whether the fuel contains a small amount of oil or none at all the richness air/fuel ratio is unaffected. The volume of fuel vs the volume of air is not changed by whether the fuel has oil in it or not.
Conceptually, if you kept adding oil in the gas to the point where the fuel is no longer a combustible mixture, it wouldn’t burn in the designed cycle. And I suppose the opposite of that is to what you refer, removing oil would make it more combustible, but would not change the air/fuel ratio but would affect the combustion cycle (premature) in ways that have nothing to do with richness or leanness, but rather manipulating the flash point of the fuel. You can not make a four stroke run richer simply by adding oil to the gas, but you CAN lubricate your valves :smirk:
 

SRAD97750

Moderator
Staff member
Negative sir. Whether the fuel contains a small amount of oil or none at all the richness air/fuel ratio is unaffected. The volume of fuel vs the volume of air is not changed by whether the fuel has oil in it or not.
Conceptually, if you kept adding oil in the gas to the point where the fuel is no longer a combustible mixture, it wouldn’t burn in the designed cycle. And I suppose the opposite of that is to what you refer, removing oil would make it more combustible, but would not change the air/fuel ratio but would affect the combustion cycle (premature) in ways that have nothing to do with richness or leanness, but rather manipulating the flash point of the fuel. You can not make a four stroke run richer simply by adding oil to the gas, but you CAN lubricate your valves :smirk:
Steve is 100% correct.
I know it's early and everything, but you might want to re-read the concept you have laid out. An edit perhaps.

Oil taking up any percentage of volume of fuel will absolutely change the air/fuel mixture per unit of measure.
If you add 2T oil to fuel, a gallon of air/fuel mixture will be 3-5% less fuel, which gives a leaner air/fuel mix per unit of measure.
The volume now must include the 3rd component. You cant exclude the non combustible, it is now part of the fluid. Air is fluid as well.
This also means less energy content per gallon.

This thread is WAY off. OP hasn't even addressed one thing from his first reply received. -BIG DAN:thumb:
 
There is always a back and forth discussion here . Not trying to kiss ass , but Dan is right... mixture is disributed throught the main jet . And pilot jet . Don't ask which oil , or ratio , that will just start another " discussion " . Just stick with what your manual says .
 
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