Is it true to pour Marvel Mystery oil in carb for rx-7 that's been sitting awhile to lube apex seals?? What else to do or check for poor performance due to car not being used for awhile?

 

if you have a carb, your probably in the wrong section unless you converted to a carb....what year is your car?

 

If budget allows:
Change/bleed/replace ALL fluids/filters/hoses/lines/plugs and anything else that can dryrot/crack/biodegrade/slip/burst/pop/leak/rust/oxidize/breakdown etc.
Some premix for the 1st several tanks of gas will help while you test MOP oil usage. Think of it as premix insurance until you verify oil burnage. A little down the carb or in the spark plug holes will help too. It helps with compression building and lubrication until the OMP primes itself and clears any air in the oil lines.

 

Damn..you beat me to it.

 

Better to remove the leading (lower) spark plugs and dump an ounce of oil into each chamber. Then crank engine over by hand a few times. While that sits, change ALL fluids (including fuel).

Start the car, and let it gradually warm up while looking for problems. Then follow standard breaking procedures. Drive below 3000 for he first 500 miles, change the oil, then gradually increase the RPMs until you are able to hit readline at around 1500 miles. If the engine will die, it will die in the first few months.