is my motor too low

[Cloud_9]

Re: is my motor too low

the general ruls of thumb.
1 inch above the bottom of the hull. the plan of the hull and the cav plate need to be parralell.sorry about the spelling.
the water is riseing as it leaves the hull thats why the cav plate has to be higher.
if you have a pod.
it 1 inch for every foot away from the transom. ( up that is )
Cheers Cloud 9

[Chimo]

Re: is my motor too low

Howdy

Cloud 9 's rules are cool too. However, with twins on a deep vee one needed to look for outcome indicators that allowed benchmarks and milestones to be assessed as indicated by steering effort sweet-spot achievement and general boat running attitudes etc.

If the motor (s) is (are) at the right height (check the cave plate / foils when running, at medium to high speed cruise) and the steering effort is optimized then height (s) as set according to other rules like C 9s should be correct.

All this is part of the fun of boating is it not, ie lifting and dropping motors til one is happy!

Chimo

[Kleyny]

Re: is my motor too low

looks like i know what i'm doing this week.

thanks guys. it looked too low to me. at cruise speed with the 4 blokes the cav plate couldnt even be seen.(not that it has 4 in it very often)

i'll try 2 holes and see how she goes.

neil

[QuinnyDory]

Re: is my motor too low

Honky Dory,
I think i have the same hull as you but i have a 40hp Merc 2str. So I took a few pictures of how mine was setup (Im happy with it so far) just in case it helps.

First I trimmed to where the ventilation plate is more or less inline (parallel) with the real hull bottom.

I did your saw test and it looked like 1/2 inch below hull.



Then from the back and side also:





With this setup I generally do not get any prop ventillation - only sometimes in very disturbed water under hard acceleration.

cheers. Darren.

[tigermullet]

Re: is my motor too low

By the looks I'd be doing some adjusting on the trailer as well.

I have the same reservations about that rear roller as Finga. From the photographs it appears that there might not be adequate support for the stern and the weight of the motor. Could be a false perception, of course.

Have seen some boats develop a real hook from a heavy motor bearing down on the stern without adequate support. Bearing in mind that most boats spend much more time on the trailer than they ever do on the water, over the years weight can distort some boats

[seatime]

Re: is my motor too low

It appears from the pics that those hulls have a cut-away keel, can see now why it doesn't sit on the 1st roller.

QuinnyDory's pics raises a question however. I'm pretty sure those centering skids aren't supposed to be touching the hull. All of the weight of an alloy boat should be supported on the keel rollers, with the bilge skid boards holding the boat upright. Those short skids at right angles and next to the keel rollers, are for guiding the keel onto the rollers, not supporting the hull.

[QuinnyDory]

Re: is my motor too low

It appears from the pics that those hulls have a cut-away keel, can see now why it doesn't sit on the 1st roller.

QuinnyDory's pics raises a question however. I'm pretty sure those centering skids aren't supposed to be touching the hull. All of the weight of an alloy boat should be supported on the keel rollers, with the bilge skid boards holding the boat upright. Those short skids at right angles and next to the keel rollers, are for guiding the keel onto the rollers, not supporting the hull.

Gelsec,
Your right, the rear roller is a lower roller by design i think so u do not have to fully dunk the trailer. The 3 keel rollers in front bear most of the weight. The centering skids may carry a little - barely, but not shown in the large skids slightly further out that take at least equal weight. Id be interested to know if anyone really thinks there would be sag here over time - I doubt it as the cutaway keel looks pretty solid "by design". Trailer is a brooker, not the most expensive but time will tell.

[colo]

Re: is my motor too low

Hi
What you said about the cavatation plate is right, it should be some were bettween leavel with the transom to an 1 inch below. All boats are differnt and need defernt hights due to engine hp, boat, and propeler, stanless props can genraly run a higher engine high than alloy. Trim you engine untill it is parrel with the keel and then take a mesurement (not whens its trimed rite down) with a 60hp you should be able to run it slightly hire probly 1/2 to 3/4 of an inch. The boat wont sit any deeper in the water with extra weight in it once its on the plan. As far as your tralier setup what you said is right to if you lift the back rollers higher you will have to push the keel up and over it whitch would be a pain. Hope some of this was a help to you.

[seatime]

Re: is my motor too low

Hi colo

could you explain how a stainless prop can run higher than an alloy prop, and how much higher are we talking about? I'm considering getting a SS prop.

cheers
Steve

p.s. please download and use iSpell b4 replying.