checkmate 283 convincor prop question
 

i have a 1997 checkmate 283 convincor with twin 454s and bravo 1 drives. Im running 25p 3 blade mirage props and if i go above half throttle out of the hole they will start to cavitate thats with the drives all the way down. Also at top end im only getting around 67 mph at about 5500 rpm which i think is over max operating speed for 330hp 454. Basically i think my boat is under propped anyh advice or input would be much appreciated. thanks

Definitely wanna lower your RPMs. 5500 is way too high... a set of 27's may be your answer..plus you'll break 70 mph! Imho. Lemme know what you're gonna do with your 25's. I might be willing to buy one and give it a shot on mine. 454 mag.. Bravo 1..and I've been seeking a 24 for use as a spare??

jtcustoms,

Depending on your ultimate goals, we can get you test propellers in the 3 and 4 blade variety. 3 blades will most likely be the better speed propellers but 4 blades have advantages as well.
Call us and we can help.

Brett

I also have a 1997 Convincor with twins (502 MPIs). When I purchased the boat it had Labbed 29" Mirage Plus props. The boat would run 80 MPH on GPS at 4700 RPM but had a hard time getting on plane. Later I added power upgrades, extension boxes and Labbed 30" Bravo One props (4 Blade). The boat had no problem planning but I never had good top speed runs. There was a boat with your engines tested by Hot Boat mag that they claimed ran 80 MPH with 31" props (If I remember correctly) but I think a 4 blade 26" or 28" would work best on your boat. Good luck.

thank you everyone for the input. i have decided to have my props reworked by h&h propellar. gave them my numbers and they said it would be no problem to reshape to get the pitch i need. ill let you guys know how i make out. thanks again

Thanks JT,

Please let us know the ultimate rpm and speed differences you get after the adjustments

Brett