(85 gs, 12a, stock Nikki, stock fuel pump, deleted omp, running 1oz 2stroke per gallon of gas) So I've notice that about a month after doing an oil change my oil level on the dip stick will slowly rise to the point where it's above the max level mark.

Also my oil has a slight gasoline smell to it....

So my question is what are my options? Can I continue running it like this? Is an engine rebuild required?

 

If your seals and oil control rings are worn enough it could be the cause. I suspect you are
burning a lot of oil as well in addition to the premix.

 

Totally normal for a rotary engine. There's a lot of surface area for fuel to get into the oil, plus the whole bit hwere the intake port gets covered by the side of the rotor.

It's an old enough issue that Mazda had a way to do rapid oil changes during endurance-racing pit stops. You don't normally notice it because the OMP is constantly siphoning oil back out. I suspect that the RX-8's legendary thirst for oil is due to the additional scraper rings and side exhaust ports preventing much fuel from getting past the oil control rings, so the true volume of OMP flow is seen.

When I do oil changes, I fill the engine to the low mark, then change it when it gets to the full mark, then save the old oil and use it in my VW which processes oil at an alarming rate through worn valve guides.

 

Great! Thanks for the replies. I'm glad a rebuild is not necessary.