Prop selection center console

[WaterDR]

What would you suggest for a 22' center console? 150 yam 4 stroke?

 

[GA_Boater]

Look at the stickie on top of this forum titled Read This First. The guys will need a lot more info to give you the best advice.

 

[WaterDR]

It's a custom boat. Started life as a 1991 offshore. Completely overhauled. We have no data.

We just need a starting point. Thinking 17 or 19p.

 

[Georgesalmon]

no prop on the motor? 17 might be a good start. a lot depends on how you load the boat.

 

[Sea Rider]

Go for a wot run while lightly loaded on flat calm water cond and check achieved max wot rpm, check if inside safe wot factory range for that OB, ideal within middle to max wot rpm. Can maximize prop by playing with pitches to perform nicely if in need to move more load or passengers.

Happy Boating

 

[steelespike]

If we are talking a blind selection a 17" is a good start. If you have a prop get us the size(under the prop nut)
Do a lightly loaded test run get us the wot rpm and gps speed.If you look up "Yamaha performance reports"
There are hundreds.

 

[b.gagnon]

I would think a 15 would do.... 4-strokes need to turn about 6k @ WOT..... I don't think a 17 will get you there, but if it is a light boat you may get away with it.

 

[dingbat]

I'd start at 17". Tried a 15" on my old 20' Grady. Not enough bit for a boat that heavy

 

[b.gagnon]

Generally lower pitch = More hole shot, and rpms's (good for a heavy boat).... You can only compare to the same type of prop. A 15p prop could have so much cup to it that it could turn a lower RPM than a 17p. There is always an exception and your 20' grady may be one of them...

 

[dingbat]

Generally lower pitch = More hole shot, and rpms's (good for a heavy boat)....

Assuming the prop has sufficient surface area to efficiently transfer the HP....Changing from a 17" to 12" prop on a 300hp motor will not increase the hole shoot

#4200 avg. load. Nail it, Lots of RPM,lots of slip, slow coming out of the hole. 15" stiletto, plenty of cup, too much HP and not enough prop. 17" Stiletto ran at max. RPM, great hole shot.

 

[b.gagnon]

Like I said "GENERALLY"....Most boats (non Bass) are not overpowered. Depending on his weight, He is borderline under powered! It would be difficult to compare a progressive pitch high rake prop like a Stiletto to a standard prop. He really needs to get more info on his hull to get any good idea. A 22' boat could be anywhere between 21-23' and could be + or - 500lbs. Is he holding 50 ,100, 150, gallons of fuel??? I think a 17p will get him in the low to Mid end of the range with a light load. Unfortunately he is going to have to get his hands on some props to find out! 4-strokes generally need to get to the upper RPM range to be in the proper torque curve to make max HP. I have a heavy 20' CC with a 2-stroke 150, and with a 17 pitch only turn 5100rpm.... There is so so so much not known in this case, engine height,deadrise,weight,fuel, prop diameter,pitch..... I don't think he will ever be able to turn more than a 17p. For his sake I hope he has trim tabs! It really is just a guess at this point!