prop size and boat speed 1977 fish nautiq

forgot to mention the boat has a 351 pcm with the 1.23 to 1 tranny

with a clean bottom, i am reading 4700 rpm

people on the forum seem to get close to 40 mph out of the boat which makes me think that i don't have enough prop on the boat....i do have the tower which gives it a bit more weight but i think the boat should still top out at 35 mph....what do you guys think?

the motor was installed new in late 2001 by the previous owner and has just under 400 hours on it.... it really runs like an animal. Would a 4 blade prop benefit the performance??

As far as the prop goes, the prop shop said it was correct based on their calculator i think is a 13 x 14 if i am not mistaken. The motor is a pcm 351 installed new in 2001...somewhere around 260hp. I did not own the boat with the previous engine, but the person i bought it from said that this motor has much more power than the last. The boat has an incredible hole shot which leads me to beleive the prop shop was wrong with their calculations and it needs an additional inch or two of pitch. thanks
Michael

Unfortunately, I don't have a fish nautique. But 27 Knots? That's around 32 MPH, right? With a 1.23:1 gear. Plus an eight foot beam plus 500 pounds of fuel plus 3700 pound deep vee hull plus the tuna tower. I think that's about right. The prop sounds right based on the rpm. The people running a fish naughtique at 40 MPH probable have a big block engine.

Buster, I just got my ’89 Fish Nautique this May so I do not have a lot of experience on this boat. But here’s what I got, rebuilt PCM 351, stock other than electronic ignition, 1.23 PCM gear, and I cannot remember the prop size, maybe 14x14, not sure here. WOT 4,100 rpm’s @ 37 mph on the GPS. I generally cruise at about 3,000 rpm’s @ 26-27 mph. I was told by a former CC dealer that this is right on for what the ‘Fish’ did new with that set up. AT 4700 rpm you may be a little under propped, at least for what the ’89 PCM manual states (WOT 4000 to 4400). I really cannot relate to the 10gph doesn’t sound too bad especially considering my Jersey burns about 35gph of oil, I have not got a handle on the fuel usage on the 'Fish'. You got a really good lookin’ boat, I love that color, and the leaning post and with the additional weight and resistance of the tower you may not be that far off. Check the max rpm for that year of the PCM 351. What brand of leaning post did you install, I am considering adding one this winter.
Hope this helps, Jerry

thanks for all the info... i think that i am going to just shop around for a bigger wheel for the boat.

you guys probably know this but re-propping a boat is science, try calling michigan wheel up in mich and talk to one of their engineers, have all your info ready, hieght,wieght,eyes, you know what i mean.. they have got me out of a jam many times you. try there website

Just for reference, I'm running a 13x12 on a Cuddy with a 1:1 and a 350 OMC. WOT is 4300 RPM at 36 MPH on smooth water. This boat has the same hull as the Fish with a little more weight and a place to hide behind when it is throwing spray