Help with scarab sport set up???????

[302Sport]

I have a 30ft scarab sport with 250 Yamaha carbed motors........spinning 23P mirage plus @ 5300RPM @ 59 MPH.............This seems slow for what other people are saying their scarabs do....any input????? what if i jack the motors and put low water Pick ups????? should i try different props???

[fyremanbil]

My Scarab 30 with 235 OMC's ran about 47 on GPS, so 59 seems OK.

[302Sport]

did you have a bracket??? I was that fast with 200 Yami's.......

[STV_Keith]

Where are the 250's supposed to make peak power? I would prop the boat to run just a bit past that. 5300rpm sounds kind of low. Are you turning them in or out? Have you tried 22 Bravo's? What is the diameter of the Mirage+?

LWP and moving the gearcases up would theoretically help. Did on mine. How far down are you now?

[302Sport]

i havent tried the bravos yet..........and my motors are the highest they will go right now without a jack plate.........how much of a difference does turing the motors in or out make????

[STV_Keith]

I've heard many things on the in vs out. Mine spin out right now. Eventually, I will try in, just to do it.

The Bravo's may help with cruise speed and stern lift. Might be time to build a lift plate like I did. This plate let me move the motors up 4-3/4" total on the highest holes. Just some standard 3/4" T-6061 alum plate with the holes in the right places.

[302Sport]

how much do you think jackplates will help???

[STV_Keith]

Hard to say without knowing how deep you are now. What's the setback you have and what's the measurement from the bottom at the transom in front of the gearcases to the C/L of the propshaft?

I'm at 24" setback and the PS C/L is 1-1/2" below the bottom. I believe that with these gearcases and props, ideal is about 1" lower than my current setup. When I re-bracket the boat, I will be going with jackplates instead though.

To give you an idea...with the same props/setup, the boat was 5mph faster on top when I raised the engines the first 2". The next 2 inches added only 1mph, but it was also hotter out on my second outing. Hard to say the exact difference.

[GTO GEORGE]

I have a 302 with a Stainless Marine bracket, probably a 24" set back with 3 Liter 250 Mercs and with 21" Mirage Plus it turns 6000 and a little over 60 with lite fuel and two people. I've entertained the idea of trying more engine height, but haven't got around to it. I also have a pipe radar arch so I have quite a bit of windage to over come, also.

[kimswang]

I've heard many things on the in vs out. Mine spin out right now. Eventually, I will try in, just to do it.

The Bravo's may help with cruise speed and stern lift. Might be time to build a lift plate like I did. This plate let me move the motors up 4-3/4" total on the highest holes. Just some standard 3/4" T-6061 alum plate with the holes in the right places.

Those plates looks good Keith. I ordered mine in 1/2", and they look too wimpy to even try. Decided to use the plates and weld them on this winter with reinforcement fitted in to match the rest of it...

[STV_Keith]

Hey Kim, if you want to try my plates, just let me know. They are now on the floor in the garage since I put the jackplates on last weekend.

[USEDPARTS]

My 30 Panther is spinnin 21 mirage's in @5500rpm. The best ive seen on GPS is 71 but my motas are in my boat....LOL
I picked up about 4 mph spinnin in verses spinnin out. It changes the handleing charicteristics drastically

[STV_Keith]

When you say it changed the handling...in what way? What is your drive gear ratio?

[kimswang]

Hey Kim, if you want to try my plates, just let me know. They are now on the floor in the garage since I put the jackplates on last weekend.

Thanks Keith, I might just take you up on that until I can find a welder with a plasma cutter...

It looks good with those jacks on there. What did you decide to do with respect to paint?

[STV_Keith]

Still looking. Gotta get it figured out in the next 2 weeks for SURE.