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 GDSD 32+ mph cavitation issues 
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Joined: Thu Dec 30, 2010 5:48 am
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Location: Palmer, Alaska
Post GDSD 32+ mph cavitation issues
I strapped my GDSD on a lowe 1652 today and gave her a whirl... The prop keeps coming out of the water no matter what I do to the trim when I start going past 30mph. It spanks the rev limiter (4350 RPM). Has anyone ever tried bending the trim tabs on the skeg to try and hold the motor into the water better at high speed? I think once I'm done with my cam/piston/rockers and a higher pitched prop I could see 35mph but not if I cant even hold the prop in the water!


Sat Jun 30, 2012 1:19 am
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Joined: Fri Apr 13, 2012 3:01 pm
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Location: Eagle River, Alaska
Post Re: GDSD 32+ mph cavitation issues
Bend the two tabs on the sides up to help hold the prop down in the water at speed. Was having the same issue till i did it to mine. That is what they are for, bendingnthe main skeg for right/left is recommended if you have the 3 blade, but not a huge issue for me with weight distributed correctly.


Sat Jun 30, 2012 2:07 am
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Joined: Mon Feb 16, 2009 6:09 pm
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Location: Cypress, TX
Post Re: GDSD 32+ mph cavitation issues
X2 the tabs on the back. Mine did it too once I could get my boat over 33. Just a small bend up and problem was solved.


Sat Jun 30, 2012 8:14 am
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Joined: Thu Feb 02, 2012 12:53 am
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Location: Prairieville, LA
Post GDSD 32+ mph cavitation issues
I just did it to mine this week and it was immediately a lot better. I've still got a little fine tuning to do, but it's a clear difference.


Sat Jun 30, 2012 8:52 am
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Location: Palmer, Alaska
Post Re: GDSD 32+ mph cavitation issues
I wasn't able to keep the prop from coming out of the water still. I'm going to cut the tabs off and weld some new ones on at a little more aggressive angle with a wider tab... maybe a little lower on the skeg. I tried bending them a little at a time until they were bent pretty far up, it helped a little but I still have to hold the motor down in the water. Total pain in the butt.


Sat Jun 30, 2012 11:07 pm
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Post Re: GDSD 32+ mph cavitation issues
Get a motor with trim and be done with it

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1850 Uncle J
Delta Performance level 4 GTR


Sat Jun 30, 2012 11:12 pm
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Joined: Thu Dec 30, 2010 5:48 am
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Location: Palmer, Alaska
Post Re: GDSD 32+ mph cavitation issues
See my post in the classifieds for a GDSD frame :)


Sun Jul 01, 2012 12:34 am
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Post Re: GDSD 32+ mph cavitation issues
Lol I saw that and almost posted on it but held off. Seeing that the motor is already modded that's an excellent choice. Find yourself a gt frame ;-)

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1850 Uncle J
Delta Performance level 4 GTR


Sun Jul 01, 2012 1:03 am
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Location: Meraux,La.
Post Re: GDSD 32+ mph cavitation issues
Hmmm I know a boy with a modded gdsd and has no issues keeping his down. It did take some bending to find the sweet spot though. Once it's up and running the motor will run fine,it just pops out every so often. Not enough to worry about.


Sun Jul 01, 2012 7:59 am
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Joined: Thu Dec 30, 2010 5:48 am
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Location: Palmer, Alaska
Post Re: GDSD 32+ mph cavitation issues
All the bending in the world wasn't going to fix this... I cut the trim tabs off, made some new ones about 2x the size of the originals, then welded them on at a steeper angle. When I took it out for a test run it was still popping out a little, I bent them slightly more, and no more popping out of the water! I lost 1 mph, but that's worth it for not coming out of the water. Holds 30mph with 2x 200lb guys in deep water with some light waves, 31 by myself.


Thu Jul 05, 2012 7:42 pm
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Joined: Thu Dec 30, 2010 5:48 am
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Location: Palmer, Alaska
Post Re: GDSD 32+ mph cavitation issues
*update...
The big trim tab works great... in deep water... I took it through some slop yesterday and there was tons of salad hanging on it. I need to dress it up a little better... R&D project I guess.


Sun Jul 08, 2012 12:42 am
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Joined: Mon Oct 19, 2009 6:38 pm
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Post Re: GDSD 32+ mph cavitation issues
I was gonna say quit leaning/pushing down on the handle.....lol


Sun Jul 08, 2012 1:50 am
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