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Article: Rebuilding Forensic's Spectra 20 Part 2

namba860

Havasu Marine Specialties
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I could never figure out why trim tabs on a jet. I removed them from mine. Im assuming that your trying to fix a porpoise problem? You really don't see any listing on a jet boat due to its shallow deadrise so you wouldn't use them for that and jets don't need any help out of the hole so you wouldn't use them for that? Nice looking boat good job!
 

SBMech

Fixes Broken Stuff
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Thank you Bob for a great write up!

Can't wait to see part 3 :thumbup:
 

RiverDave

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I could never figure out why trim tabs on a jet. I removed them from mine. Im assuming that your trying to fix a porpoise problem? You really don't see any listing on a jet boat due to its shallow deadrise so you wouldn't use them for that and jets don't need any help out of the hole so you wouldn't use them for that? Nice looking boat good job!

It's not to solve a leaning problem. The trim tabs are for when the water is rough out. If you are cruising you can maintain a flat and level attitude of the boat, that you can't do without them. Just my .02 but I think jets need trim tabs (or cav plates) more than an I/O does, because there's a lot less "leverage" with a jet then there is with a prop. Boat rides 100 times better in rough water now.

RD
 

Marine Industries West

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It is unconventional to install tabs on a jet boat. IMO, tabs or a control plate system are pretty useful on any type of boat. Not always necessary, but in the right application they can be a good asset to the boat. The Spectra is a wide and heavy 20 foot boat. The boat didn't have a any handling issues in our initial water test other than being a little sluggish to get on plane. After the addition of the tabs and the new nozzle setup, the boat comes on plane like a 19 Daytona. Even with the tabs all the way up. In our final water test, I never moved the tabs down, and the Spectra was flat out impressive on handling thru chop and get up and go. The boat takes a great set and did not drive like a heavy jet boat.
 

Forensic

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I made the the decision early on to go with the tabs. After running it and playing with them, I wouldn't have another boat without them.
Now the boat gives holiday chop the middle finger.
 
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