cavitation plate location?

[dw711]

hey all! I am finally installing my after market trim/tilt on 1982 90 merc inline 6 and would like to know the proper heigth of the cavitation plate in regards to the bottom of the boat.It seems to cavitate easily in fairly small turns when i am alone in the boat.right now the plate is about an inch or so above the bottom of the boat.The new trim/tilt sets the motor back 6" I would think that would help substatially,would'nt it.The boat is a 15'v hull its not a real deep v though (87 thundercraft)<br /><br />thanks

 

[mbb]

Re: cavitation plate location?

Ive got an 81 90 hp merc. Motor is mounted about 4" above bottom of boat on heavy 17' Mckee. With the old merc prop, it would cavitate and blow out in sharp turns, with a stilletto prop, it WONT blow out, I can cavitate it 100, 200, or as many rpms as I want just by trimming out. The stilletto hangs on great. Unfortunately, no one can tell you what max ht you can put motor at will be, also the old mercs have all holes, not slots for the lower bolts, so its not as easy to jack up and adjust motor to try it, like you can do on an OMC. <br /><br />With the setback you get from the T/T you can probably go up a little more.

 

[dw711]

Re: cavitation plate location?

it's me again im not trying to seem impatient but my computer shows replies posted for the above topic nut when i try to retrieve them there is nothing there.Just wondering if i did something wrong. <br /><br />thankyou

 

[dw711]

Re: cavitation plate location?

thanks mbb I was under the impression that the plate should be below the bottom of the boat.

 

[dw711]

Re: cavitation plate location?

not asking for a gaurantee but do you think it should go up more?the set back on the t/t is going to drop it a little if anything.

 

[TONY H]

Re: cavitation plate location?

Cavitation plate should be even with bottom of boat or a smidge lower. when the boat is up on plane, the cavitation plate should be riding on the water.