Ranger 370V with 150EFI 23P Tempest Plus Lower RPMs

[sanannbassman]

I replaced my motor a few years ago and just recently re-setup the motor. I put replaced with a 23P Tempest on when the boat was at 6" PTP. I raised it to the highest position on the transom and am at about 4". The boat gets out of the hole very well but i am only turning about 5K RPM. I am getting to about 53MPH. The prop has large plugs (holes). I noticed that I can trim up all the way and the boat slows down about 3 to 4 MPH and i do lose some water pressure. It appears on my gauge to be about 20PSI when i am hooked up just below full "up" position.

[Rip Bass]

Okay,so what is your question? Just off hand,I’d say put on a 6” jack plate and set the prop at about 3.5” under and see where that puts you,speed and rpm wise. You might need to drop down to a 21 Tempest+ to get your rpm up. That hull doesn’t have much built in set back so a small,plate can help a lot.

[techman]

check your plugs.i had a bad coil on
when I checked the plugs one looked really good. that cylinder wasn't firing.

[mdtritn21]

Probably one cylinder not firing and your at least one mounting hole too high since you don't have a plate. That motor is a 2.4 L high revving motor that needs to run closer to 5800 rpm's so a 21 tempest would be a better choice.