Hi all, I'm a new rotary owner and my car does not have an OMP. My questions for you guys are:
1.) would I be able to replace the OMP with an original part or after market part?
2.) what is a good fuel:oil ratio for my 12a?

as I stated before I am new to rotarys so anything will help!

 

Used OMP's are probably available but you also need lines and nozzles. Not as familiar with first gens but it may be more trouble than it's worth at this point. Premix ratio with no OMP is 1 oz. per gallon. And on 1st gens it may actually be more effective than the OMP. That doesn't mean you're baking a cake at the gas pump. I guesstimate based on how much fuel I anticipate to fill up and use the little window on the side of a quart bottle.

 

Everything I've read says 1oz per gal with no omp.

 

I would source a used omp and lines and purchase a new omp gasket and omp internal o-ring kit and use the original omp. With it you can cut the premise down to a half ounce of premix per gallon of gas, which is helpful if you have a catalytic converter.