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 Boat not planing 
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Joined: Thu Sep 21, 2017 6:47 pm
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Post Boat not planing
I have a 1658 riveted jon boat with a modified go devil 23hp motor on it. I rebuilt the motor from the ground up and really happy with it's performance so far.

Biggest problem I have is the front of the boat always seems to low even with just me in it it's pushing water up front. If I move as far rearward as possible I gain a mph or 2.

As far as weight on the boat there is nothing up front, motor and gas tank are in the rear.

Anyway to adjust the motor/boat to raise the front of the boat up? I know on a outboard I'd just adjust the trim but not sure what I have for options on this motor. Thanks Dan


Sun Jun 10, 2018 8:36 am
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Joined: Mon Dec 31, 2012 11:07 pm
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Location: West Monroe, LA
Post Re: Boat not planing
Sounds like the only solution you're gonna have with that combo is to cut the transom down some to lower the mount point so the motor doesn't lift the rear/lever the front down as much.

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Sun Jun 10, 2018 10:45 am
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Location: North Pole, Alaska
Post Re: Boat not planing
Check for a hook in the bottom just fwd of the transom. A very small hook will cause what you describe, especially with a boat as wide as yours and the limited torque of a longtail.

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Sun Jun 10, 2018 1:49 pm
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Post Re: Boat not planing
Transom is 16in tall.

No hook in the rear of the boat except the weld line at the end.


Sun Jun 10, 2018 4:00 pm
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Post Re: Boat not planing
Yeah, fill a few sandbags and put them in the rear of the boat. You have a problem few have ever experienced. Rake is too short because you have so much lift with the wide and light boat. Most of these boats never experience a problem with the rake being too short.

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Sun Jun 10, 2018 4:48 pm
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Joined: Thu Sep 21, 2017 6:47 pm
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Post Re: Boat not planing
Sand bags worked just like you thought they would. Started with 5 bags (200lbs) at the very rear of the boat and it planned great. Didnt effect top speed but seemed like a smoother ride.

More testing is needed to fine tune it as i got rained out but i think as little as 2 bags might be enough.


Mon Jun 18, 2018 2:45 pm
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Location: south Florida
Post Re: Boat not planing
Suggest you replace sandbags with ballast cooler full of beer and ice! :mrgreen:
Is the "modified" 23 HP GD motor a longtail?

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Tue Jun 19, 2018 4:57 pm
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Post Re: Boat not planing
Yup it is a long tail. When i bought the boat it had a 16hp vanguard on it and i wanted more speed so i thought ill just build a monster 23hp precision cam, heads .050 lower than stock, total seal gapless rings, billet valve retainers with double coil springs, custom dual 1in straight pipes, idk what else but everything i could think of to get it to go faster.

Problem is i didnt understand its a longtail and there just not made for speed.

Oh and dont worry the sand bags are just for testing but i think the fully stocked cooler sounds like the best idea.


Tue Jun 19, 2018 6:37 pm
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Post Re: Boat not planing
Longtails run faster on longer/narrower hulls than yours. Yours will run very shallow (shallower than most) and carry a good load, but you'd pick up more speed if you subtracted 8 inches from the width, and maintain the load carrying by adding a couple ft of length. The problem you have is a nice one to have for all reasons except speed, hence the problem lol. A surface drive would suit that boat better, if for no other reason it would add 100lbs at the transom and get the bow up because of the drive angle.

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Tue Jun 19, 2018 7:25 pm
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Post Re: Boat not planing
I can live with it doing 20mph for now, maybe adding the right amount of weight in the rear will get me 1 mph or more if im not pushing water the whole time.

I wouldnt want to give up the boat tho because running shallows is what i really need, not a crazy amount of mud or weeds to worry about on the wapsi just sandy shallows and trees that might go 100% across the river.

If i ever find a great deal on a 35hp surface drive that would be my dream motor, i would love to modify that motor to the wall, not sure if it doable but i would definitely try to put a tiny turbo on it as well.


Wed Jun 20, 2018 6:21 am
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