Mercruiser 2017 4.5L 200HP v6 - prop suggestions

[jamesdgreen2016]

Hi! I have the engine above. It's attached to a Bayliner VR5 bow rider also 2017. I have a 19 pitch 4 blade prop on it currently. It's apparently suitable for the engine according to the dealer I got the boat from, which came with a 19 pitch 3 blade prop Ive never used. I like my 4 blade it's just that the engine hits 5200 sometimes 5400 RPM which its not supposed to be able to do (thats another topic altogether, but it does).

With just a couple people on the boat it runs to lets say 5400RPM. Very good hole shot and 43mph top speed.
Fully loaded it runs to 4800 or so rmp. And half loaded maybe 5000 rpm.

Now, I understand the engine can probably safely take 5200RPM because its the same engine as the 250HP variant that goes to 5200rpm.

What Im wondering is should I go to a 3 or 4 blade 20" or 21" and whats that going to do to my hole shot and top end?

I like to do deep water slalom ski starts so I dont want the boat to take forever to speed up and I dont care if it goes 43 or 46mph at the high end.

Would moving to a 4 blade 20" lower that top end 5400RPM to closer to 5000RPM and maintain a decent hole shot you think? Or 3 blade 20", or 21"?

 

[Scott Danforth]

going up in pitch will kill your hole shot

to me it sounds like its prop'd right. with one one or two people on board, back off the throttle a bit

 

[jamesdgreen2016]

Thanks, and for these engines the new 200HP and 250HP 4.5l mercs its supposed to be the same engine just the 250hp one allows rpms to hit 5200 while the 200HP one allows them to hit 4800. Mine being the 200HP version its not supposed to let the engine get that high because of a limiter, but it does let it - the boat dealer when I told them said not to worry just dont run it at WOT for long periods of time and its fine hitting the 5200 range. I guess I wanted to do a gut cheque ive been running it with this prop this is the 3rd season now.

 

[QBhoy]

Stick the 3 blade it came with back on it and get some data. 4 blade props as a base for getting a prop right, isn’t easy and mostly doesn’t play by the general rules. If there even is such a thing.
Don’t trust your tachometer either. Generally these modern mercs will usually limit about 150 rpm over their max rpm range stated. As a guide.