premix?
 

whats the proper fuel to premix ratio? i would like to delete the omp from the car and was wondering how much premix should be put in on a full tank in a 91 fc? thanks in advance for any input

most people will tell you .5 ounces to 1 ounce per gallon of gas. I use 1 ounce myself

thank you for the input... any other helpful information would be great... any specific brands? how to get accurate measurment?

It depends-
 

The amount depends on your setup.

If you still have an operational OMP, then less is better- that is where the 1/2 oz per gallon comes from.

If you have removed your OMP, you need more-that is where the 1 oz per gallon comes from.

Of course, if you have removed your OMP on your 91, your car isn't going to run anyway. If you have taken measures to avoid that issue, you wouldn't be asking these simple questions.

I'm just saying...

Estimate the amount of oil you need to treat the gas you are about to pump. Add the oil to the gas tank before pumping the gas. Pump the gas, then note your estimate vs. the actual amount you should have added.

If you are over a little, that is ok.

If you are under a little, you can add the amount you estimated to be short.

This becomes kind of like a science project: estimates and guesses, measuring and corrections yielding unknown results.

Have fun!


This will become a 5 page argument.

With the MOP removed, the common range seems to be 128:1 - 100:1 for a street driven car (1 - 1.3oz/gallon)

On the track some people step this up to 75:1, or even as rich as 50:1. This may be excessive, and you will definitely catch a buzz off the exhaust.

Of course people will have different opinions. I mix about 100:1 on my S4 TII motor, and it has been fine for the last 3 years. If you have a perfectly functional metered oil system, I wouldn't even bother premixing on a street car. I only removed my system because plastic oil injector lines were getting pretty shitty, and I could blow air both directions through 3 of the injectors (which should flow one way only, like a check valve).

So, roughtly 8oz for an engine with a functioning omp and 16 with out would be good for a sixteen gallon tank, right?

Right. I usually run my car to a little under a quarter tank, then just add 10-11oz of 2-stroke, and fill up with 10 gallons of gas.

no omp about 18oz or so full tank. i use the walmart brand 2 stroke works just fine.
you'll know when you've put too much, it'll start smoking alot

I go by the 1 oz per gallon method. I just buy the 2 stroke oil in an 8 oz. container and fill up 8 gallons at a time, pouring the oil in first so the fuel washes down any oil that may have coated the filler neck.