Anti ventilation plate height

[Bowhunter1661]

Would would work. Say that three times fast. But I would use something that will never rot. Like a cutting board. Buy a cheap on and cut 10"X1 1/2" or however thick your transom is. Then glue them together or screw them together. Presto, no rot.

I plan on upgrading the 2x10 I used to a 15"x8" piece of 1/4" aluminum plate so I never have to worry about rot.

 

[scoobeb]

Good idea,ha. I just bought 3 cutting boards at walmart. I will take a couple drops of crazy glue to hold the shim in place then drop the motor on top of it. Or I can just screw it in to the top of the transom,that won't ever move or rot with the hard plastic shim and ss screws,does that sound like a good idea?

 

[Bowhunter1661]

Sounds like a plan to me. Just put some silicone in the screw holes so water doesn't get into the board

 

[Bowhunter1661]

Or you could bolt your motor to the transom and go as high as you like. Even if the clamps only grab the top of the transom, put your shins in. Get your height right, then bolt it

 

[scoobeb]

Well,I have to go to Walmart to get a solid cutting board,the ones I bought have like a lip around the whole thing to catch like liquid and stuff like that,I want a solid cutting board. So my plan is to cut out one shim at a time,stack one up,see were the clamps line up on the transom and the av plate,if I have more room I will go higher. I'm going to get as close as possible making sure I have plenty of clamp biting on the transom. Once I get the desired height then I will screw the plastic into the top and I will put a few drops of silicone in the holes to. I don't think water could get in there because it's on top of the transom but better safe then sorry. Just a thought,wouldn't the plastic eventually get brittle due to the outside elements,like sun,etc.....

 

[Bowhunter1661]

I suppose the cutting boards could get brittle. But I have used the cheap ones for fish cleaning and leave them out all year long and they never seem to change state. I have seen on numerous occasions where others have used plastic cutting boards for projects on boats and they are fine.

Very curious to see how this goes for you.

I also have a 9.9 for restricted lakes, I adjusted the motor up to the point my clamps had about 3/4" of bite on the transom. Now for a larger motor with more torque it may not me all that great but it worked fine for the little 9.9. I made my shims the exact thickness of the transom so that the clamps actually clamped down on the 1/4" worth of board they were touching.

Ran that way for several months and never had the slightest bit of loosening of the clamps or movement. If I didn't have the jack plate I would have just got my height right and bolted it down. Certainly no worries about it comming off then. And no need for clamps.

 

[Bowhunter1661]

Ops I meant my clamps were attached to the transom 3/4 of the way. 3/4" is not a good thing.

 

[scoobeb]

If you look at the pictures of my transom you will see there is a lip there,the clamps will actually slip under that lip so it's kind of like extra security. I may just leave it were it is now only if there isn't enough bite for the clamps when I put the shim under it. I think it will be fine either way but I may gain a little top end speed. Like one person said I just may be way over thinking this whole thing and should just leave it as be. It's not like it's several inches below the keel,it's around a inch or two at the very max.

 

[scoobeb]

It's a light flat bottom jon boat,I think this motor will make this boat fly no matter what,that's just imo. I can live with it as long as there's no rooster tail and water coming in the boat. I just need to find a nice flat calm day and test it out to see were im at,if I hit 30mph or better I'm doing real good.

 

[scoobeb]

So here is what I'm going to do. First ,cut out two shims made out of the cutting board as Bowhunter 1661 described,second,put the shims on one at a time then the motor to see how close I can come to level with the keel as I possibly can get. When I get the height right I will screw the shims in from the top to hold them in place so when I put the engine on they won't move. Third,mount the engine and go catch some fish. One advantage I get from putting the motor up an inch or so is more prop clearance from hitting rocks or oysters that I run near and over to fish at. I'm sure if I mount it on the transom and go it will perform great but why not do it right the first time. Now if I can't get enough of the clamps to bite on the transom then I'm just mounting it on the transom and going fishing,lol but I should be able to move it some with good bite on the transom. Thank you to everyone who has helped me,especially Bowhunter 1661,thanks. :mrgreen:

 

[scoobeb]

Ok,I tried to move it up on the transom,problem is the clamps won't be under that lip and doesn't feel secure to me so scratch that idea. All I can do is lay it on the transom and go or get a jack plate for it. So now I'm stuck with a decision. I guess I'm going to mount it and go for now and hope for the best.

 

[huntinfool]

I raised mine up a hole. But my question is should I just be on plane when checking or should I be wide open?
Just on plane, mine is still under in front and a hair out in back. ( I know this is due to trim) We were fighting a good chop, so my wife didn't feel comfortable going wide open.

Should I go up another?

 

[scoobeb]

So I went back to the 20hp,the 25hp was just to much to handle without electric start or power tilt and trim. The 20hp is almost 40lbs lighter and so much easier to start and control. The 25 was a awesome motor but just to hard to start manually and was hard to tilt. The 20hp is perfect for a 16ft jon boat.