Set up

[lundfisherman]

I have a 98 1660 pro-v, and would like to know if it is worth raising my motor 1 hole.The motor is a 70 horse OMC.I've played with props and settled on a 15 pitch turbo 1.This gives me about 33.5MPH on gps,with good hole shot and about 5500rpms,with just me and 5350 with a buddy,with no cavitation even in tight turns. The bottom of the hull is about flush with the cavitation plate.I've read alot of articles on this motor and they recomend proping it at close to 6000rpms.Would raising the motor one hole add 100-150rpms?I would just like to get every ounce of speed out of it thank in advance.

[KP]

I am not at all familiar with your specific boat or motor. But the RPM's your talking about seem low. If your motor is currently mounted all the way down on the transom, I would think you could raise it at least one hole, maybe two. But, I'd get that input from someone more familiar with your setup.

Yes, raising the motor will increase your RPM's and increase your speed. How much I don't know. I do know raising my 30 HP motor two holes on my little Lund increased my RPM's so much I was able to use a one pitch larger prop. My total increase in speed was 5 MPH from the setup I started with.

[lundfisherman]

The motor is in the top hole.I think that would be on the transome.

[lundfisherman]

back to the top

[John]

Hiya!!

My rig is a little smaller than yours, so hopefully you can get a little help from this.

If I am correct, your MAX rpm should be at 6000 (not totally sure on this). If correct, you have plenty of room for increases in speed.

First, I would start by moving the motor up 2 holes. If you get excessive cavitation, move it down one hole. The more motor out of the water, the faster it will go...this includes the hull. EXERCISE CAUTION though....if you do not get water to cool the engine, it will be done quickly....If you can, install a pressure guage to see what's happening.

By raising 1 hole, you should see about 100..maybe 150 increase in RPM. Hole shot should still be good and as long as the prop is still grabbing, handling should still be good as well.

I moved my motor (50 hp) up one hole, and am going to try the next hole up this spring, to see what I get oug of it.

Good luck and have fun tinkering!!