[THEFERMANATOR]

I had this same problem with my grandfathers pontoon boat. It has an 85HP SUZUKI that is oil injected. YAMAHA uses the same basic oil injection pump that SUZUKI uses. But the PENNZOIL oil was thinner than the SUZUKI oil that the pump was calibrated for, and it was pumping almost twice as much oil as it did with the SUZUKI oil. The MIKUNI pump is VERY particular of what oil you put in it. Switched back to SUZUKI oil(which in bulk is about the same as PENNZOIL at WAL-MART). Drained the oil tank and refilled it with the fresh SUZUKI oil, purged the air from the lines. And took it out and ran it for 30 minutes on the lake and it has run great since. I run the PENNZOIL in my eVINRUDE premixing, but it didn't work with the oil injection system.