Top speed on new boat

jnk111

Seaman Apprentice
Joined
Aug 4, 2007
Messages
35
I have a 17' 1988 bayliner cuddy with a 88 85hp force. I just purchased this boat about three weeks ago. I was wondering what I should expect the top speed to be. Currently I am seeing about 25 (speedo). The boat was/ is moored on a slip on the river. The previous owner thought that it should do around 35, but due to the algae build-up it would only do 25.

I pulled the boat out this past Monday and cleaned the bottom. I also did a compression test, 125,125,130. I replaced the fuel pump and adjusted the mixture earlier. I did notice that a little fuel seemed to "seep" out of the fuel line connections (almost all of the connections) so I replaced some of the hoses and all of the clamps to get a better seal.

The one thing that concerned me was that the bottom spark plug looked almost new compared to the others (they were not bad though), only about a 1/4 inch of carbon on the outer edge of the plug the rest was clean (it is firing I checked). That is the cylinder that measured 130. I did replace all the plugs anyway.


I was going to try and get the boat back in the water tomorrow and try it out. The owner was upfront with me about everthing as far as what he knew was wrong, trailer light was out etc.. so I have no real reason not to believe that he was hiding anything. I was having some problems with it killing when putting it into gear (the reason for fuel pump and mixture adjustment) but it seems to have just needed the idle turned up. I also installed a tach to get a better idea on where it is running. It runs well though. The motor looks brand new but it just has very low hours on it. I hope this makes sense.

Thanks for any input.
 

QuadManiac

Petty Officer 1st Class
Joined
Jul 2, 2007
Messages
391
Re: Top speed on new boat

My 91 18' bowrider with a 90HP will do 35 (GPS) with 500lbs of crew and a full gas tank. The speedo says between 25 and 30 at WOT, depending on what phase the moon is in, I think.

Buy, borrow or steal a GPS to determine your true speed. Pitot speedos are not worth the air in thier tubes, except as an indicator of movement, in my humble opinion.
 

jnk111

Seaman Apprentice
Joined
Aug 4, 2007
Messages
35
Re: Top speed on new boat

My 91 18' bowrider with a 90HP will do 35 (GPS) with 500lbs of crew and a full gas tank. The speedo says between 25 and 30 at WOT, depending on what phase the moon is in, I think.


What rpms are you at?


I picked up some speed (as per speedo, and I could defiantly feel it) after the bottom was cleaned. From 25 to 33 or so. The problem is after installing the tach I see I am only running at 4200rpm.
 
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