Hi Saturday morning was my first time out this year. 271 Sr-1 502 gen V bravo 1. It fires on the first crank. Let it warm up to 175, and oil pressure is pretty much around 40-60. WOT 5000 rpms, it runs about 52 mph on my 22P B1 (GPS). Being quite pleased with the way it's running I put 10 gals at the marina, hoping to enrich the old gas in the tank. I was holding 25 gallons of last years stabilized gas. I went back out and experienced surge for the first time ever on this boat. 5000 rpm for 3-4 secs then drops to 4800 for 1 sec and back up to 5000.
When I backed down the throttle to 3200, it surged between 3200 and 3000 with the same frequency. I was within a minute of the marina, and pulled up to a dock, at idle 800 rpm the surge was barely noticeable, while at 1000, it was surging again. I pulled the boat out. While at home, I started and ran it on the muffs at idle for about 10 mins, no surge. Took off the fuel filter for analysis. Poured the gas into a glass jar, it was golden, no signs of rust or water. The filter material was a normal color. The gas didn't smell like varnish, but didn't smell sweet either. What should I do to narrow down my problem?
When I backed down the throttle to 3200, it surged between 3200 and 3000 with the same frequency. I was within a minute of the marina, and pulled up to a dock, at idle 800 rpm the surge was barely noticeable, while at 1000, it was surging again. I pulled the boat out. While at home, I started and ran it on the muffs at idle for about 10 mins, no surge. Took off the fuel filter for analysis. Poured the gas into a glass jar, it was golden, no signs of rust or water. The filter material was a normal color. The gas didn't smell like varnish, but didn't smell sweet either. What should I do to narrow down my problem?