Four winns foam

[bulachip]

I have a 1987 four winns 170 bowrider. The boat has a 4.3l and only reaches 41-43mph top speed with the correct prop setup (I have tried a bunch 19 21 23 and all are about the same top end, but with varying RPMs).

In addition even with a 19 pitch it is slow to plane, and the boat feels heavy.

I have heard that there could be wet foam, but do not know where to look, or what to look for. I have looked everywhere and do not see anything that looks like foam (assuming it looks like spray foam used in a house or something)

Is it possiable that it was all removed already, and if so , why is my boat so slow. Others with my setup claim high 40's and even 50!

 

[Bob_VT]

Re: Four winns foam

How did you look under the deck? Take a look in the restoration section for more info.

 

[DBreskin]

Re: Four winns foam

You are looking for something like spray foam in a house. It's under the deck of your boat and not visible without taking up part of your deck.
Do you know the rated speed for your boat? If not, you can find out by downloading the owner's manual from the Manufacturer website. 43mph might be the rated speed.
The owner's manual can also tell you the max RPM. It may be your engine is out of tune and not achieving rated power.

Good luck!

 

[oops!]

Re: Four winns foam

one of the simplest ways to check for wet foam is to weigh the boat.

compare it to factory specs.....if you are over even by 50 lbs.......you are wet. it is very likely with the age of the boat

btw....if you are wet......you might be rot as well !

 

[smokeonthewater]

Re: Four winns foam

Do you know how to operate the trim for the best hole shot and while underway for max speed..... If not, that could be your problem