Is there a clue where to start?
 

My 1st gen 12a carbed rx-7, is running very strong up until about 5000prm.
after 5000rpm i think it`s running lean, Misfireing, Hesitating. well it`s not good above 5000.

Can someody please help me where to start?

Floater level is to high or to low, i cant see the level line in the windows.

Fuel filter, caburattor, false air, vacuum probems? maybe.

I have an usa engine and a european carburettor.

thanx.

Weak link in first gen is the fuel pump.They were barely capable when new.If it revs cleanly in first gear and starts to play up in other gears do a flow test for volume and pressure and also change out fuel filter.

Fuel filter, pickup in tank clogged.

I`m starting with the filter.
 

Thanks for replies. I`m starting with the filter. But if that dont work, i change the fuel-pump.
Does anybody know how mutch the pump should deliver? what pressure an how many liters in hour?

I'd try filter first, then drop the tank, only takes 30 minutes. Also a chance to replace 30 year old fuel lines and sand and paint the tank, even if the inside is clean. Good luck!

3.7-4.7 psi and 1.1 litres/min from FSM for factory unmodded car so any mods will raise the required volume.