Searay Sundancer 420 Prop Size Help/Opinion

[curtdeason]

I have a 1990 Searay Sundancer 420 with cat 375 hp 3208 engines.I have 22" by 26 pitch 3 blade props, Sea Ray says this is correct props for my boat when I gave them serial number. Boat is supposed to turn 2800 rpm at woot I am only turning 2500, had a cat mechanic check out engines and he said engines are performing correct said props were too big. I have talked to several prop shops and get different opinions about what I need to re-pitch props too. I would like to know if their are any other owners out there with a sun dancer 420 with similar engines and what props you have before I spend money to get props resized.

 

[acman2]

Did you ever figure out what you need ? I have the same boat and need the same info.

Thank you

 

[curtdeason]

im sorry I bought a business last August and have not been on here since I have not figured it out yet have talked to several prop shops and got several opinions most say to go down two pitch sizes and they suggest going to four blade if you do you have to go down two more pitch sizes I recently purchased four blade 22x22 pitch I will install soon I will let you know outcome how many RPM does your boat turn now and what speed

thanks

 

[swaterhouse]

Each boat will be different, an inch of pitch should equal about 100 rpm.

Before you do anything you need to make sure your bottom and running gear are clean and your engines are healthy. If your engines are good but bottom is dirty and your down 300 rpm, you still need to drop rpm but probably not as much as a clean bottom running 300 rpm low.

Best thing to do for your particular boat is load it your "average" load, fuel, water, gear, people etc. and do a few runs to get a good average WOT reading. If from that your down 2-300 rpm you need to drop 2-3" of pitch. If that was me I would drop 2", and retest.

You may be surprised, your speed may not drop much if at all, but you will definitely get better mileage and have longer lasting engines!

 

[becnme]

I would also add to check the accuracy of your tacs with a photo tac if the mechanic did not do it.