Motor Mount Height, want to do it right!

[rost495]

21 foot Hydra sport. Transom repaired.

Am now ordering a CMC manual jack plate and will hang a used 200 Evinrude on the plate.

Want to make the best use of the plate as to further adjustments.

Need to know where is best for motor height to start with and to set the jack plate at that height and then be able to come up like 3 inches or down 2 or how should I set it all? I can take a stab at it and set it to the minimum and have only 5 inches up movement in it.

Thanks, Jeff

 

[Reel Poor]

Re: Motor Mount Height, want to do it right!

In theory, for every inch of setback you have you can raise the engine half of an inch.

Be sure to install a water pressure guage, it will let you know if you are picking up enough water or not.

 

[rost495]

Re: Motor Mount Height, want to do it right!

Have read where the water pressure gauges drive folks nuts? More now, less later, depends on salinity etc....

Anyway have a fin on this motor as it came. not looking in my repair book right now but that should be on the cav plate I'm assuming, IE the largest plate there. And that should be even with the bottom of the boat?

So do I allow only room to come up 5 inches? Do I take into account the setback for sure with no issues.

Not a tunnel hull type at all, basically a v hull so its not a shallow water boat at all if that makes any difference. I'm assuming will not run in less than 18 inches or 24 inches.

What I'm after is not so much shallow water, as doing it right and best for the motor. Less motor in the water is good for drag, but what is correct?

OR a source of how to do this correctly?

Thanks, Jeff

 

[Reel Poor]

Re: Motor Mount Height, want to do it right!

Quote "Have read where the water pressure gauges drive folks nuts? More now, less later, depends on salinity etc...."

Thats BS, It's a reference guage. If your going to run a jack plate you need the guage to let you know if you have raised the enging to high, to the point it can't pick up water anymore.

Quote "Anyway have a fin on this motor as it came. not looking in my repair book right now but that should be on the cav plate I'm assuming, IE the largest plate there."

If your talking about one of these, take it off.

Quote "So do I allow only room to come up 5 inches? Do I take into account the setback for sure with no issues."

How much setback does your jackplate provide?

 

[rost495]

Re: Motor Mount Height, want to do it right!

CMC manual jackplate. Not sure on setback YET. Will look and get back to ya. I think 4 inches.

On the fin, I have a small boat with a tunnel that really could use a fin to help hold the water down etc...

Have heard good things about them. But the good thing is that its off right now and I don't have to put it right back on. Can leave it off and see how life is.

I hope I'm clear on this motor thing, only reason I want a plate at all is to be able to tweak the motor if I make a mistake in drillign the holes for height. IE with the motor only I have one shot at it and if it doesn't perform...... with a manual plate I have a bit of play. Just need to know how to do it right.

Will have the water gauge regardless, Thanks.

Thanks for putting up with me.

In the meantime, am lookign for the bushings that flare the drain tubes-- anyone have a source? And I keep hearing 3m to seal holes. Well we are small town USA. I need a source. I suspect Wally world won't have it and thats even a 25 minute trip for me. Love living in the country but getting things is a pain.

Thanks, Jeff

 

[rost495]

Re: Motor Mount Height, want to do it right!

BTW setback is 5.5 inches and 5 inches of height adjustment.

 

[Reel Poor]

Re: Motor Mount Height, want to do it right!

Here is a diagram of the way a transom mounted outboard engine should be mounted.

Click Here to see the drain plug I would recommend. Just drill the hole and then coat the raw wood in the hole with enough fiberglass resin to seal the wood. Then install the garboard plug from the outside.

Here is the drain tube you asked about.
Click Here For Drain Tubes

Here is the 3M 5200 Sealer that would be recommended.

You can get all this right here at iboats Mega Mall