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View Full Version : Any scarab1 owners??



BiesemeyerSquirt
09-20-2004, 03:13 PM
I recently purchased a 87 scarab1 with a 7.4 in it. So far I have enjoyed the boat. My question concerns trim tabs. The boat seems to take awhile to plane and chine walks bad over 70 mph. I know the extra weight of the 454 has a little to do with it, but do you think tabs will help correct these problems?

Squirtin Thunder
09-21-2004, 07:37 PM
One of the jobs that tabs do is help hold the bow down, If you use then to stop the chine walking you will loose speed. The reason most boats chine walk is that the drive is too high, center of thrust. What I mean is the engine and boat are faster than set-up. So I recomend a shorter foot, lower unit or short shaft. I have heard that the drive set-back can help this problem too. Does this boat have a delta-pad???
Jim

SHAKE-YO-AZZ
09-23-2004, 11:48 PM
yeap trim taps would be good

rent free
10-17-2004, 07:04 AM
I own an 85 21 with stock 350 260hp. running a reworked 19 stainless 3blade
gpsd.@63 with 1/4 tank & 1pass. boat used to porpiuse on top end.hole shot
was nothing but wicked(3 to 4sec.to plane).I put bennet dual ram trim tabs on to correct porpiuse :hammerhea
I lost about 4mph.

ECeptor
10-17-2004, 05:30 PM
I just read a tech article in Powerboat mag (Teague on Tech) and a guy with a Fountain had the same problem - chine walk. They recommended correcting with the trim tabs by setting both down. They even recommended adding collars to the tab cylinders to prevent them from fully retracting. Although it will add drag, they advised chine walk was a pretty serious problem.
They also mentioned something about the rotation of the prop and how some boats are more sensitive than others to that.
Anyway, sounds like keeping the tabs down just a little bit should cure the problem.