Me and one of my friends just acquired a Mazda pickup truck and When I opened the hood I realized it was a rotary so I started doing research on Mazda rotary trucks and found the REPU but the one we have is not a REPU it’s the next generation body style of the B-series pick up trucks so I’m assuming it’s a swap but idk witch rotary engine is in it I’m thinking it’s an old 13b if anyone knows any help is greatly appreciated

 

I know this is old, but seeing as no one answered you I thought I would. If you look on the driver's side top of the motor, near the spout where engine oil is added to the engine, you will see either "12A" or "13B" stamped on the engine. That will tell you whether the motor is a 13B (1.3L) or the smaller 12A (1.1L). If it is a very old rotary (pre-RX-7), 13B motors were in the RX-4, RX-3 wagon, RX-5 (Cosmo) and REPU (Rotary Engine Pick Up). The other models that were pre-RX7 did not come with 13B's from the factory. Also, the first generation RX-7 (1979-1985) came with a 12A except for the GSL-SE model, which came with a fuel injected 13B. There may have been another trim level first generation RX-7 that came from the factory with a 13B, but that's the best I can do from memory at this time.