[swanseajack]

Hi All! I Have A Dell Quay Dory 13 With A 40hp Mid Eighties Mariner With Which I Wish I Could Get More Out Of!..... She Seems To Motor Along Ok At About 60%power But When I Throttle Up I Seem To Get A Void Of Water Around My Prop! Cavitation I Think U Call It...the Previous Owner Used Her Primarily As A Skiing Boat So Must Have Been Getting A Bit Nearer Top Speed???. Two Problems Im Guessin It Can Be Are That My Cav Plate Is Sitting 3 Inches Above The Hull Ie. Engine To Short Or The Pitch On The Prop Is Wrong For Speed I Want To Get, It Is 12...any Advice Welcome.....

 

[LutonRoy]

Hi this might be helpful, here's the link

http://www.boat-ed.com/fl/course/p3-13_boatperform.htm

it also has other useful information on boating.

hope it helps.

 

[ChrisP]

The ideal is to have the engine set with the cav plate within 1 inch of the bottom of the hull.

I guess the engine is not power trim so take the trim pin out and adjust the engine in as much as you can. Pin in the hole closest to the hull. Try it on the water, if the nose is too low but the cavitation is better try it out one hole on the pin. Keep trimming it out until the cavitation returns then take it in a hole.

12 pitch doesn't sound too bad, try the trim first that fix is free. If it doesn't work give us another shout.

 

[Manxman]

Most engines need the cav plate one inch below the bottom of the transom, is there room to drop it down three inches?

How high have you got the engine trimmed, to high and it will cavatate.

 

[swanseajack]

cheers all.... just had a look and the trim pin is out as far as it can.i will work it in and check for improvement next trip...what i cant do though is lower the engine anymore as the transom has been lowered 3 inches already!!!..checked that site out good info cheers wise ones......