how fast should my 82 procraft fish n ski go with 82 evinrude 150 hp

[jldsomething]

hey guys i just bought a 82 procraft fish n ski 17 and half ft long its a really nice boat for the age very soild and has a 82 evinrude 150 hp on it i went out the other day at like 6 am when nobody was on the lake and the water was very very calm and trimed out and running wot i could do about 47 mph i really think this boat should be in the 50mph range it has a 21 pitch prop on it and at wot on a calm day it will over rev to about 5800 to 6000 rpms and i belive i should be at a 23 pitch prop insted but if the water gets a little choppy at wot and trimed up it only tacs at like 5200 to 5300 now im no expert with boats this is my second boat and its my first to have push button tilt and trim and all of this is with 2 avarge size ppl and a full take of gas. would a high pitch prop help me gain top end speed? would it hurt my take off? and what about when the watter is a bit choppy would it run below 5000 rpms and hurt my speed? also the evinrude is mounted right on the transom no transom jack and there is the small black fin on the motor as well. thanks guy just i dont know where i should start to gain speed. compression is good i checked it before i bought it.

 

[jimmbo]

Re: how fast should my 82 procraft fish n ski go with 82 evinrude 150 hp

The rpm range for that motor is 4500-5500. 5800-6000 is a bit high on it. A 23 would drop you down about 400rpm. With a performance SS prop you could raise the engine off the transom a couple of holes that will give you more speed and few more rpms.

I had an 18 ft runabout with a 98 150hp. with the 19in alum it did 49mph at 5400rpm. I put a 22 Raker on it, the speed went up about 1 1/2 mph, at 4800. I tried a 20in and the rpm went to 5200 at about the same speed. I raised the engine up a couple of holes and the speed went up to 54mph around 5400rpm