Volvo Penta 5.7 1997

by Brian
(Michigan )

Four wins speed boat. 5.7 Volvo penta Throttle body. Full throttle takes off great and run good for a couple of minutes and then acts blogged. It will run strong to 3500 rpm and then goes to 2800-3000 no higher. At full throttle (3500rpm, use to get up to 4000-4500 when the prop was new, now it has a couple dings in it not sure if that’s the cause) It will run at 3000 rpm no higher. I can stop the boat and then give full throttle and sometimes it will get going in the beginning but then bogges again. Sometimes when running it will slow to 2000rpm and then stay there for a little before reving up again.(whole time full throttle). I haven’t used it much this year so it is at half a tank of fuel, the tank is from last fall and I did put stabilize in it. Today I changed the fuel filter. I forgot to last fall. I put fuel injector cleaner in it. What other things should I try.