Help with raising transom / planing issue - 20hp yamaha

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yama33
Posts: 3
Joined: 04 Aug 2013, 12:12
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Help with raising transom / planing issue - 20hp yamaha

Post by yama33 »

Good day. I recently picked up a 20hp yamaha 4 stroke and am having issues planing a 14.5ft v hull aluminum that is loaded pretty heavy with batteries/trolling motor etc.

Before changing props etc I need to get the transom height fixed. I noticed that the yammy is 23in from cav plate to top of where it sits on the transom. The boat is 20in so its sitting at least 3in too low in the water.

The motor doesn't appear to have strong enough bolt holes to not use the clamps, so the transom needs to be raised in order to clamp it.

Thinking either the mini-jacker or building a transom extension. I don't really want the motor further back and I see the mini jacker does this.

If I build something, what strength of aluminum will I want for the front/back plates, or should I look at aluminum angle?

Any pictures/thoughts welcome.

Thanks

yama33
Posts: 3
Joined: 04 Aug 2013, 12:12
6

Help with raising transom / planing issue - 20hp yamaha

Post by yama33 »

should also mention that the motor is a tiller. mini jacker would move back 3 inches?

lovedr79
Posts: 2566
Joined: 07 Mar 2011, 19:58
8
Location: Harrisonburg, Va.

Help with raising transom / planing issue - 20hp yamaha

Post by lovedr79 »

my boat did the same thing. i added a 4 blade 9p prop and added a transom riser. my cav plate is about 0.5"-1.0" above the bottom. solved the planing issue and porposing issue. i also moved my fuel tank and battery forward of the console.
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Lowe 10' jon

sawmill
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Joined: 07 Jun 2012, 22:30
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Help with raising transom / planing issue - 20hp yamaha

Post by sawmill »

Can you post a pic of your transom? Is it flat across the top of the boat or is there a slight dip down?

lovedr79
Posts: 2566
Joined: 07 Mar 2011, 19:58
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Location: Harrisonburg, Va.

Help with raising transom / planing issue - 20hp yamaha

Post by lovedr79 »

It was flat, now it has a 5" riser. Not the best pic.
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Lowe 10' jon

edlacy
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Joined: 22 Jul 2013, 23:03
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Help with raising transom / planing issue - 20hp yamaha

Post by edlacy »

Would like to see some more pics of how you did the transom.
Thanks.

lovedr79
Posts: 2566
Joined: 07 Mar 2011, 19:58
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Location: Harrisonburg, Va.

Help with raising transom / planing issue - 20hp yamaha

Post by lovedr79 »

if i remember i will take some more pics of it. mine is 1/4" aluminum plate. with 2 2x2 square tube sandwiched inbetween. and bolted over transom. i bought it off a guy on here that didnt need it anymore.
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Lowe 10' jon

lovedr79
Posts: 2566
Joined: 07 Mar 2011, 19:58
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Location: Harrisonburg, Va.

Help with raising transom / planing issue - 20hp yamaha

Post by lovedr79 »

here you go, this is where mine came from:
https://www.tinboats.net/forum/viewtopic ... 7&start=15

i saw it and asked where he got it and he sold it to me.
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edlacy
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Joined: 22 Jul 2013, 23:03
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Help with raising transom / planing issue - 20hp yamaha

Post by edlacy »

Thanks for the picture........

lovedr79
Posts: 2566
Joined: 07 Mar 2011, 19:58
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Location: Harrisonburg, Va.

Help with raising transom / planing issue - 20hp yamaha

Post by lovedr79 »

You're welcome. That thing made all the difference in the world. I also moved some weight forward. I removed my starting battery and tied into my front tm battery and went to a 3 gallon tank that I put under ny steering console. I may still add some balast weights under the front deck. The four blade prop helped tremendously too. I was at the point of just selling my motor for something bigger but finally got it worked out.
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Lowe 10' jon

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