Planing problems

[Peter G]

Help, I think my boat may be a lemon. I've just bought a second hand aquasport 215 CC and repowered it with brand new 150 ETEC. Unfortunately the boat won't sit at speeds of between 12 and 17 knots. It will either rop back to 10 knots or get up n the plane and want to go to 20. All this is great when the weather is good but in choppy seas 20 knots is too fast and 10 too slow. Has anyone else had the same problem and is there an easy fix?

[bdtsr]

Try keeping the motor trimmed all the way down. If your boat has trim tabs, try running with the tabs down some, more if needed. Keeping the weight more forward will also help.

[Capt. Bob]

That's because it's a planing hull not a displacement hull. Add to the fact that it is short, light and your helm is somewhat forward.
The perfect recipe for a rough (and often wet) ride. Nothing "wrong" with the boat, just the nature of the beast.

[Peter G]

Thanks for those comments.

Does anyone own or know of someone who has the same or similar boat and have they had the same problem. If not, how is it set up? Which engine and prop (diameter and pitch)?

[Capt. Bob]

Peter, is this your first boat?

[Peter G]

No its my fourth. I have two others at the moment, a pontoon boat and 18ft runabout as well. The 18 footer is up for sale but it did not have these problems. In fact it sat nicely on speeds of 12 to 20 knots and being smalller trimmed a lot easier and was more responsive to weight distribution. Also, the driving station is forward not in the centre and this may have helped.

I have taken the aquasport back to a marine mechanic to fit a hydrofoil but he said that this will not help the problem. He believes that adjusting engine height and getting the right propellor size and pitch will fix it, hence the question regarding what other people are running on the same boat.

The local propellor salesman also said that same thing and suggested a prop of smaler diameter but all of the literature and avice from others said this shouldn't make any difference. Any help is appreciated.

thanks

Peter

[GoneFission]

I agree with your mechanic - get the right motor height and prop - the rest will work out.  

A foil will not help until you fix the bigger problems, and then foils don't work well on Aquasport outboard models - check out this thread:

viewtopic.php?f=2&t=679&st=0&sk=t&sd=a&start=45

Good luck!

[Peter G]

I agree, it probably needs to be set up right but short of trying half a dozen different props I'm not sure what to do. If anyone has the same engine on a similar boat I would really like to know what prop they are running.

[GoneFission]

I would guess that a 14" diameter 3 or 4 blade prop with a 17" pitch would be a good starting point for your 215 with a 150.  

Good luck!

[Dhadley]

I'd agree. A 4 blade with tail lift will help a lot. Not sure I agree with the salesman about less diameter. Tabs would help a lot too.

Maxing out the set up is critical. What kind of rpm can you get now with an average load? What brand & style prop do you have?

[gw204]

I ran a 15 x 17 3-blade AL prop on my old 20' Grady CC and it performed great.  I would start with something like that....and make sure the engine height is correct.