Should I install a Hydrofoil on my 74 Chrysler 45 HP????

myanni74

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Joined
Mar 19, 2009
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14
Looking for some advise. I currently have a 1974 MFG 15' Gypsy with a Chrysler 45HP outboard of the same vintage. I am having trouble getting the boat on plane with another adult and 2 children on it. I literally have to put all three people in the bow to get it to settle down and get on plane.

I think it might be slightly underpowered for what I am trying to get out of it. I usually run the boat out to a local bay and do a bit of fishing and back. On occasion, the water might get choppy, but for the most part, it is not to bad.

I recently had the prop reconditioned back to manufacturer specifications to make sure it was not the prop, but it did not make enough of a difference.

I was wondering if installing a hydrofoil on it would help the boat to get on plane faster and stop the bow up ride that I am getting with it?

Any suggestions if anyone has had experience with this??
 

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Frank Acampora

Supreme Mariner
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Jan 19, 2007
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12,004
Re: Should I install a Hydrofoil on my 74 Chrysler 45 HP????

No doubt about it: You are underpowered. If you have a higher pitch prop like 12 1/2 or 13 1/2 You can try to get a lower pitch prop (11 1/2) for better acceleration, but top speed will suffer some. Contrary to most opinions, I believe that you might try a foil. It may help or may not. You won't know until you try it. For that reason, try to find a used one cheap.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,074
Re: Should I install a Hydrofoil on my 74 Chrysler 45 HP????

First, what rpm at wot are you running?Your motor should run about 5500rpm at wot.The wrong prop will give poor results.A hydrofoil will help in somecases.But if you ain't got the umph to get on plane it won't help.
Do a compression/spark test.Post your results.J
 

myanni74

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Mar 19, 2009
Messages
14
Re: Should I install a Hydrofoil on my 74 Chrysler 45 HP????

I did a compression test on the motor earlier this season and I got 99 and 101 on each of the cylinders. I recently replaced the coil, wires, and plugs on the motor because I was not getting a good spark. I am good there now.

I am running a stock 12 1/2 inch prop on the motor, which when the boat is loaded correctly and only 2 people on board can plane out alright and can do 27 mph on the GPS.

The issue comes in when I have more than two people on it. I thought that the hydrofoil can help with that issue. I found one on boatfix.com for $39.00 and a sport clip on ebay for 9.99. I am just not sure that it will do anything. I guess every manufacturer plays up their products to be the next best thing, but before I go investing the $50, I am just trying to see if it was worth trying.
 

tater76

Senior Chief Petty Officer
Joined
May 7, 2010
Messages
712
Re: Should I install a Hydrofoil on my 74 Chrysler 45 HP????

Hey Myanni,

So I have pretty much the same setup, 73 55hp Chrysler, and a 76 16 foot trihull. I have a heck of a time getting it to plane out when my family gets on her. I have tried the foil and found it actually slows me down. I tried lower and higher pitch prop with no better results. I have good compression, and everything is tuned as it should be. I have come to the conclusion that I am just underpowered. My boat is rated for up to a 75hp, and that is what I plan to go to.
 

myanni74

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Joined
Mar 19, 2009
Messages
14
Re: Should I install a Hydrofoil on my 74 Chrysler 45 HP????

Mr Tater76,

Thank you for the feedback. I think you just saved me $100. I was actually going to try out some tabs, but now maybe I should just wait until I find a good motor in the 75hp range as well and stick that on there. The issue is that around here, finding a motor like that will be really difficult and run me about $950 - $1,200 used. I can almost wait and just upgrade the boat for that much.
 

emoney

Commander
Joined
Jul 19, 2010
Messages
2,551
Re: Should I install a Hydrofoil on my 74 Chrysler 45 HP????

You might try finding a used motor dealer that will take your engine in on
trade. If so, then you could only be out 1/2 that and probably be happy.

On a final note, where do you have your 'trim bolt'? Is the motor as far down
as it will go?
 

AirForceOne

Cadet
Joined
Aug 28, 2010
Messages
11
Re: Should I install a Hydrofoil on my 74 Chrysler 45 HP????

I tried a Stinger Hydrofoil on my 85 Bayliner Capri with the Force 85hp and it works great! Comes right out of the water and on plane and you don't notice any pitch at all.:)
 

milehighboater

Petty Officer 1st Class
Joined
Jul 28, 2009
Messages
235
Re: Should I install a Hydrofoil on my 74 Chrysler 45 HP????

My two cents is a hydrofoil will more than likely just slow you down. For a hydrofoil to work you need to be able to get the boat moving fast enough in the first place and I don't know is 27 is fast enough. If you are going to try one get a smaller one. If the package says 15-50 hp or 45-90 hp go with the smaller option. I can not remember the name of the company but they designed a foil in the shape of a teardrop that worked fairly well without the resistance of some of the t shaped ones. As far as buying a new motor, try craigslist. Don't look for a motor but look for a bad boat with a good motor. A lot of times people will unload a ugly boat for 500 bucks with a great running 75hp on the back. all you have to do is figure what to do with the boat and trailer when you are done.
 
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