Getting maximum speed from your Scarab Sport
 

Fellow Scarab Sport owners: I've had mine for about 3 years now. It is primarily for family and fun, food runs and beach stops. Been fishing on it twice (two times too many if you ask me.)

It's a year 2000 hull with twin 2005 Yamaha 300 HPDI's. During sea trial, we easily hit about 65 MPH. I have not seen those speeds since. I've played with different trim settings including the tabs and engine trim. Please reply to this thread and tell me your secrets for getting top speeds out of your Scarab Sport. (Downhill with tailwind in a hurricane do not count)

Good thread. I just bought a 99 with 2003 injected Merc 225. Solas 4 balde props 24 X 14 Best I have seen so far is 57 MPH with a full thank. I am going to try some Bravo 1 24 X 15s this week and I'll keep you all posted. I'm hoping going with a taller prop I'll be able to raise the motors 1".

I'd consider changing props. But since the broker was able to get a much higher speed out of her, I figured I should get OSO input first.

i have a 98 and i did raise my raise my engines had problem with water then i bought parts to jam water in water ports and running 3blade hit 62 or 63 that was best then tried 22 4 blade bravo that raised the whole boat out of water and i could not use much trim boat got to loose but speeds were the same in wot and cruse liked the ride better thats it but do want to try 24 bravo next

I have an 86 Scarab CC with twin Johnson V8 outboards. They were modified by Monty Racing out of FL, and made 380hp/340ft-lbs. Finished off with retrofitting Mercury CLE lower units with custom adapters. Boat has run a best of 72mph on GPS with this setup, spinning Bravo 1 15.25 x 26's (1.87 gear ratio in the CLE's).

My boat also has 28" of setback (24" Gil Brackets + 4" of jackplates). This is actually too much as the boat went 75mph with 4" less setback, but I wanted the jackplates for shallow water running and adjustability. Motor height plays into top speed too.

Have 2000 w/ twin Evinrude 225's. Running a 21" prop I got 62gps at over 6000 rpm. Bought a pair of Mirage Plus 23" over the winter. Still trying those, but got 61.5 gps so far.
My method is no tabs, motors trimmed very high and a mile stretch of smooth water. Had light load of fuel and two people on board.

Mine starts to chine walk a little above 70 as well.

http://www.myspace.com/video/stvkeit...nd-run/7659106

My old S Type was a bit of a handful over 70 as well.

Chances are during your sea trial the boat was empty, you have probably added a bunch of weight with gear and stuff for the family since then
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That most likely where your speed went.

I have a 98 with 250 Merc EFI's. Every year I seem to get a little slower, however, I do seem to get my best numbers ( 61,62 mph) with really fresh gas. I don't know my prop specs off hand, but they are whole shot props. I figure that no matter what props I put on, I'm not hitting 70, so I just keep the props that put me on plane in about 4 or 5 seconds with 8 people onboard. It works for me.

Good point. But I haven't loaded the boat with anything more than a couple of amps, speakers and subwoofers. Even when I'm almost out of fuel, I can't get close.

The only difference from the date of purchase is that it was about 45 degrees outside. But that can't really have a 10 MPH effect, can it?

Excuse my ignorance but is it a 2 stroke? If so I could believe it. I know it is a little different, but my snowmobile runs like a Scalded Dog when there is a -30*F difference. S#it I'd have to rejet or calibrate or I would burn down. 2 strokes are a different animal.

Hi Rookie,

They are 2-stroke.

My mechanic went over and checked the boat yesterday before I leave for a long weekend trip on the boat. He changed the plugs, which had lots of carbon and check some other items. On sea trial, he got it up to 61. Boat has 3/4 fuel in it, maybe 150 gallons.

Told me to put the tabs down alot, lay the throttles down, trim it way up, then start backing off the tabs until just before it begins to porpoise.

After my trip, I'm taking it in for the 100 hour service: new water pumps, the works.

When I get it back, I'll see if it gives me more.

What props are you running?

Not sure. Will check next time I am at the boat. It's kept on a lift behind a relative's house.