NOT like Theory.....

[Bon]

Hi everyone

I have a problem and still cant get answer yet..

my boat is mako 264(5000lb) one verado 250 with mirage p15. rpm at wot too low 5500
get little bit ventilation on curves and the engine is in the last hole down but
on plane the cav plate under the water about 1.5 inches
the cav plate is higer then the bottum of the boat at about 2 inches
the last owner down the engine on hole to the las because he had too much ventilation
any sulotions or ideas????
Thanks
Bono

 

[SparkieBoat]

Re: NOT like Theory.....

do you do a lot of curves? personally I raise my motors until they vent slightly on a hard turn on purpose in order to get best performance/speed/MPG out of my set up. I just slow down some on hard turns. and my cavitation plate/whale tail is usually just out of the water. sounds like you have the short shaft motor on a long shaft transom maybe. you could consider a 12" or 10" manual jack plate, getting your motor away from the hull will reduce ventilation. and actually allow you to be able to raise or lower your motor to the best sweet spot. as for your RPMs I do not know what the recommended RPMs are for your motor, but rule of thumb is you gain about 200 rpms with every pitch drop so if you should be at 5800-5900 rpms you could go with a 13 pitch. but 5500 is usually a good rpm range for most motors I have seen. do you have trim tabs?? if so you could trim them up some and it should lower your transom slightly.

 

[Bon]

Re: NOT like Theory.....

Thanks
I also think that if i getting the motor away from the hull it will be good..

this what jack plate does??

 

[SparkieBoat]

Re: NOT like Theory.....

here is a link for a 6" and a 10" manual jack plate, they do have hydrolic ones but they start around $900. the 10" set back will hold your motor 10" away from transom, I saw a 12" manual jack plate somewhere not long ago, cant remember where right now though. they also allow you to raise or lower your motor easily. once you find your sweet spot you will be good to go. http://www.iboats.com/T-H-Marine-Ma...0722228--**********.977425556--view_id.685970