motor too high? or too low?

[parrotthead04]

I have put some post on here with the same issue before and got some good replies..but havent figured it out yet and dont understand the problem so I thought I would try again.( i'm confused!!!) I have a 14' alum fishing boat with a 2001 30 yamaha short tiller. I installed a CMCpt35 power trim and tilt. Ever since I installed it I get prop slippage. The cav plate is level with the bottom of the boat. I mounted a fin on the cav plate but really didnt notice much difference. The pt-35 set the motor back about 41/2 inches. When I first installed it the cav plate was about 1" above the bottom of the hull and it slipped so I moved it down to where it is now but that made no difference. The motor and the pt-35 are both bolted and there is not much adjustment there. next time I move it I have to drill more holes so I want to get it correct. What should I do? With the setback it has....i'm thinking up...but how much? and if the motor is too low..how does it slip? With the setback...where should the cav plate be? Thanks to all in advance!!

 

[Hooty]

Re: motor too high? or too low?

Hey Ph,<br />As a general rule, for every inch of setback, you can raise the engine up 1/2". That's the beauty of setback, getting more engine out of the water. More engine out of the water, the less drag. <br />In your case, I'd have to ask how much positive trim do you have. Positive trim is swinging the gear case up away from the boat. Negitive trim is swinging the gear case in closer to the boat. It sounds like you've got to much positive trim but without seeing it.....<br />Something you might consider is loading up and having someone at a prop shop have a look. If you've got a prop problem, they'll usually help ya out and loan you a prop 'til you find something that'll work for ya.<br /><br />g'luck & c/6<br />Hooty

 

[parrotthead04]

Re: motor too high? or too low?

Its got the power trim and tilt so I can adjust it either way. When under way and it is slipping i can see that the cav plate is at or just below the waterline and i know the prop is good