Correct WOT

[ken52]

Re: Correct WOT

Wilde1j, thanks. I jumped 2 holes first instead of one at a time. I will reposition motor to center hole next. It does cavitate in sharp turns as I'm turning into another boats' wake. The AV plate is still under the water on the top hole when at wot. So as I trim for max speed(gps) and I'm still only getting 5100 rpm's does this still mean I'm under proped?

 

[wilde1j]

Re: Correct WOT

Are you allowing enough time after making a trim change for the boat to stabilize? Keep adding kickout, a little at a time, in flat water and allowing a minute or two for the boat's speed to stabilize and observe the results. If you were able to get 6000 RPM without the prop breaking free, you may not be able to get much more. Focus on the RPM and forget the speed. Speed will be there when the boat is set up right. The highest hole may be as good as it gets if the AV plate is still buried.

BTW, I would guess your rig may weigh more than you think. If you get a chance, you might weigh the rig on a public scale.

 

[ken52]

Re: Correct WOT

It was a little choppy in the gulf today, but I may be trimming to fast too. As far as weight: 1987 Evinrude(x-long shaft) 140 - 370lb, ProLine specifications show boat weights 2385 and 70gl fuel-@8lb/gl=560, giving me approx-3315lbs. Now I have dual batt, spare prop & anchor,vests,flares,etc. I believe I still should be under 4K lbs. Will know more when I drop down 1 hole and water test. I always thaught boat was heavy so I called proline and they faxed me a spec sheet and thats where I got my figures from. It was tough to get info on older boats they said, so I guess I was lucky to get what I did.

 

[ken52]

Re: Correct WOT

In the process of dropping motor back down to the hole up one where it was set, I assume at the factory. Is it possible that some boats are designed to have the AV plate sit lower in the water then what most of the suggestions I've read here suggesting that it should be above keel? Will know more after next water test!

 

[ken52]

Re: Correct WOT

Well guys I'm still getting cavitation on boat when going into turns. Not as bad as when motor was up higher. Going to put motor back in original position today. Achieved 32.7mph(gps) trimmed up with full fuel(70gl) and 2 people @ 5200rpm's. Was able to get to 5800rpm but lost speed. So it seems that this is the best I'm able to get with this prop & boat setup. Through all this I didn't accomplish much with all this moving of the motor except realizing that some boats are designed to have AV sitting lower in the water. I guess at this point the only way to raise the rpms would be to lower prop pitch from my 15p to a 13p. Thanks for all the input!