I have an all original carbureted version, 1980. I saw small spots of oil under the car, not serious, I checked the oil, it lost very little and I kept it topped off. After a couple of weeks, I took a Saturday to find it and it was one of the two small oil feel tubes to the carburetor. One rotor had been oil starved for weeks, worried me, I replaced the hose, put a few drops of oil in each throat of the carburetor. I hadn't noticed any difference driving while this happened, but I guess it happened slowly, the next day the engine started easier, seemed fresher and more peppy, if that's a word. It doesn't seem any damage was done but I had been reading about premixing before this happened and it seems like a far more consistent and safer way to protect the engine. I want to disable the oil injection and go to premix but haven't read about anyone doing this with the carbureted engine. Is it safe to premix with the carburetor? I rebuilt the carburetor because my car sat for many years before I got it but it starts and idles perfectly, even with the manual choke and I don't want to ruin that.

 

Yep, I premixed my old '83 at 1/2 Oz per Gallon with a working OMP with no impact to performance/idle. Pre mix is cheap insurance in my opinion - leave your oil injection alone and just add the premix

 

Premix is ok to do but the OMP is engineered to deliver the proper mixture at all throttle openings. So a working OMP actually will use much less oil than is required for premix. For premix you have to mix for the worst case as in WOT, so that would be like 100:1 gas to oil, so more like 1 oz per gallon. Also premix will make your exhaust much more stinky. Pros and cons, its whatever make you feel comfortable.

For a carbed car, the premix will not affect anything too much but make sure to check and replace the fuel filter more often, the oil will effect it adversely.

 

I would leave the original oil metering pump in place and leave it functioning as it should. They work fine and the 12A will last 200k miles with on original omp in place. With that said, I suggest premixing 1/2 oz of premix per gallon of gas. This would be just for extra insurance of course. Its a small enough amount that no catalytic converter or spark plug damage will occur and that the car will not smoke any more than normal.