Repower, motor height, and props

A

aassbb

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Sailfish
Just repowered a 94 Sailfish with new Suzuki 200’s. Ten hours in and performance suggests motors are mounted too low. Very slow hole shot. Have to pin it to get on plane. Won’t hold plane below 4000-4200. Cavitation plate is a few inches below edge of hull, and buried when running on plane.

We’re talking with the shop about raising the motors. I’ve read through posts on here…Should we also consider going to 4 blade props? Now would be the time as we can still turn in the new props.
 
I'm not aware of low engines ever causing hole shot issues - it's more of a top end problem because of the extra drag it creates (which isn't yet an issue at low speeds).

If the anti-ventilation plate is too low, though, yes, that definitely needs to come up. Strange that they were mounted too low to start with. You can't get into prop changes/discussions until you get the motors the right height and do more testing (including WOT).
 
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You should first get engine hight right, usually AV plate 1-2 fingers above the lower transom edge.
Once the height is right you can verify how the props work and in case change pitch and in extreme case install a 4 blade.
Changing several things together lead to confusion about what is going on, so start with the most obvious, the engine hight.
Chris
 
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I have DF200APs on my 265 express. Heavier, wider boat but here is some info to read thru regarding the 4 blade props which were a great improvement.
Also, I recommend raising the trim tabs so they don't do anything while you are trying to dial in props. Only use motor trim.

https://www.greatgrady.com/threads/265-express-suzuki-df200apxw2.29099/


to recap....
3 x16x 21.5 were too big.
3x16x18 were too small
3x16x20 were pretty good when boat was light but slipped when heavy against a raging tide.
So he tried the 4 x 15.25 x 20 props and they blew out.
4X 15.25x22 were the sweet spot.
 
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I would be more interested in figuring out why you can't hold plane below 4200 revs. Something is seriously wrong. At 4200 revs what is your GPS speed?
Do a test with trim tabs retraced as suggested. knowing the prop pitch will help figure out what's going on
 
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