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avk
05-07-2000, 10:24 PM
I have a new 99 Classic 18 with a 350 EFI running at 6000 ft altitude at Lake Tahoe. The boat is great but it seems to get a little "nervous" by wanting to slightly hobby-horsing when speeds get above 45 MPH. I have seen several posts about trim tabs so I wonder if this is the direction I shoud go and if so what type/brand is the best? I have tried all trim angles but they just want to slow the boat down. The drive unit is tight without any play in one direction or another.
Alan

johndmay
05-08-2000, 04:41 PM
Originally posted by avk:
I have a new 99 Classic 18 with a 350 EFI running at 6000 ft altitude at Lake Tahoe. The boat is great but it seems to get a little "nervous" by wanting to slightly hobby-horsing when speeds get above 45 MPH. I have seen several posts about trim tabs so I wonder if this is the direction I shoud go and if so what type/brand is the best? I have tried all trim angles but they just want to slow the boat down. The drive unit is tight without any play in one direction or another.
Alan

I guess what you're talking about is porpoising. Trim tabs will fix it, but slow the boat slightly. Mine are Bennetts, and they're fine, but I'm sure someone on this list has more knowledge of the different brands. The next line of attack is blueprinting the hull, which is what I'm doing next. Hopefully, though, tabs will be all you need to stop the porpoising.

RickR,GroveCity
05-08-2000, 06:10 PM
The Bennett SPORT tabs are better than their least expensive ones, and you get a better switch.

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RickR mailto:riggerb@aol.comriggerb@aol.com</A>

DFLOWER
05-08-2000, 08:19 PM
Before you spend big $$$ Have you considered a bolt on DOLE FIN for $30.00. I have a 95 Classic 16' with a V-8 and this boat was an embarrassment to be seen in porpoising at all speads even with the trim all the way in.
Bolted on the DOLE FIN in fifteen minutes and the problem was 100% cured. Steering was improved and the trim was even more responsive. The Fin also makes it easier to board the boat from the stern because it makes a nice foot hold when your climbing up.

I cant swear by the price, but it's cheaper than blue printing and sport tabs. It claims to work on larger boats with bravo drives but do not hold me to this. I saw one this morning on an 18' Checkmate with a Merc 150 outboard & my friend said it cured his porpoising problem also. Another claim they make is a quicker on plain out of the hole by keeping the bow down & this is also true.

Good Luck Dave

Tom on Lanier
05-12-2000, 05:47 AM
I have also had good results with hydrofoils (Doelfins)on non-Donzi boats. A word of caution: be careful about using them as a step to get into your boat as I broke the ventilation plate on the Alpha 1 outdrive doing that- bad deal.Also, be aware that the Stingray brand hydrofoil hangs off the rear of the ventilation plate and exerts much more pressure on same.Very effective but they will actually break some plates, as on my beloved Honda outboards. No problems with the Doelfin type foils.
Originally posted by avk:
I have a new 99 Classic 18 with a 350 EFI running at 6000 ft altitude at Lake Tahoe. The boat is great but it seems to get a little "nervous" by wanting to slightly hobby-horsing when speeds get above 45 MPH. I have seen several posts about trim tabs so I wonder if this is the direction I shoud go and if so what type/brand is the best? I have tried all trim angles but they just want to slow the boat down. The drive unit is tight without any play in one direction or another.
Alan



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