hydrofoil plate question

[Hislopy]

I have a 21 foot Dargel 210 fisherman series which weighs approx. 1500lbs, that is powered by a 1998 mercury 200 EFI. On a glass flat day, I try to reach WOT by i only get to 4000-4500 RPMs, going about 30mph on the GPS and then i start porposing. My question is would a hydrofoil help me reach higher speeds once the porposing stops? Thank you for your help.

 

[gss036]

Re: hydrofoil plate question

Take a look at your engine position on the transom. You might be too low in the water and need to raise it a hole or 2. I don't think the foil is the answer to your problem. You should be getting a top end of about 5500, but you really don't want to cruise at that RPM. More like 4200-4400 rpm.

 

[tashasdaddy]

Re: hydrofoil plate question

there is definately wrong with the set up. long shaft on short shaft transom, foot too deep, trim adjusted way wrong. unwanted water in the hull. wrong prop.

 

[Hislopy]

Re: hydrofoil plate question

Thank you for you reply. I have a CMC jackplate, so do you think that the shaft length would matter since i can raise the motor?

 

[gss036]

Re: hydrofoil plate question

Your answer implies that you know the shaft is too long, yes / no? If so raise the motor as high as you can get and try again.

 

[fch2cxr]

hydrofoil plate question

gss036:What do you mean by "as high as you can" with a jack plate (6 In set back) the right setting should be about 1/2 inch above the lowest point of the V bottom of the boat right??? or is there better settings???

I'm having the same issue on my 21' Stamas, which will not go any higher than 4500 RPM, runs good just won't go any higher than 4500RPM, I have a 14.5 X 19 prop, soon I will install a 17 pitch to try that out, I'm also getting 30-35 MPH by GPS, talked to the tech today and said that I should settle for that RPM range as is with in range of cruising RPMs

hydrofoilplate might help with porposing...

 

[H20Rat]

Re: hydrofoil plate question

**deleted**

 

[fch2cxr]

hydrofoil plate question

I totally agree, that is my main concern, as overloading the motor in the long run and over time is probably just as bad as over-revving the motor?

 

[gss036]

Re: hydrofoil plate question

What you need to do is to get the boat to a point where the bow stops diving into the water and holds cruise speed. I ended up raising my 225 Honda 2 holes (1 1/2") and installing a 4 blade stern lifting prop to stop my porpoising as I didn't want to have to hold the bow down with the trim tabs. I am not a tech, just trying to be helpful after going thru the same thing. I had a friend with a 24 Weldcraft w/a bracket and 225 Susuki, he never was able to totally get rid of his porpoising. Been there done that!!!!!!!

 

[fch2cxr]

hydrofoil plate question

4 blade stern lifting prop is that a special type of prop???

 

[gss036]

Re: hydrofoil plate question

It is a common prop, some are designed for "STERN LIFT" and some are designed for "Bow lift".
I have a stern lifting 4 blade SS Power Tech prop, (made for Honda) on my Honda 225. I also have a 4 blade Merc SS prop, # 48-825900A46 (RH) 19P designed for bow lift, according to the Mercury prop site. It is a used prop that I cannot use so it just sits on my shelf. It has a Flo-Torq II hub kit for Honda 225, pn# prop0076-225/ 835278Q1.