Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: 40hp 4-stroke prop?
Posted by noleman on 07/23/10 - 8:06 AM
#1
I just purchased an '03 130 w/40 hp merc 4-stroke. Prop is in fair shape and runs 6,000 WOT but out of the whole is terrible. The number on the prop is 2082R 14, so it's a 14 pitch. Any suggestions on a new prop? I typically run with a load of 400 lbs. Thx
Posted by John Fyke on 07/23/10 - 9:39 AM
#2
Tom Clark is the guy to ask. PM him and he will tell you what you need.
Posted by Joe Kriz on 07/23/10 - 10:24 AM
#3
4 strokes generally don't have the hole shot like the 2 strokes do.
What brand of prop?
Less pitch generally gives you a better hole shot and less top end speed.
However, you have to watch the redline at WOT if the pitch is too low.
I used to use a 15 pitch for water skiing and a 17 pitch for everything else.
With the 15 pitch, the boat exploded out of the water instantly...
The 17 pitch was about 2 miles an hour faster at top speed.
Posted by noleman on 07/23/10 - 10:50 AM
#4
Joe are you running the same engine/boat as me? It's a Quiksilver Black Diamond prop. I guess I'm spoiled with my 150 Verado which jumps into the air on take off.
Edited by noleman on 07/23/10 - 10:56 AM
Posted by Joe Kriz on 07/23/10 - 11:02 AM
#5
I've had a lot of Whalers and have been on a lot of Whalers...
Not much difference if propped right.
You've got a 150 Verado on a 13' ???? :)
Posted by John Fyke on 07/23/10 - 11:05 AM
#6
If you have a 150 Verado on a 13' you can go with any prop you like. Ha...
Posted by noleman on 07/23/10 - 11:28 AM
#7
no, I think a 150 would flip a 13'...I have a 19' Sea Pro w/the 150. I've read some posts that recommends putting a 13p on the 40hp, but I think it will rev too high. I might try a 15p.
Posted by Joe Kriz on 07/23/10 - 11:35 AM
#8
A 15' pitch will give you less of a hole shot than a 14 pitch.
Posted by noleman on 07/23/10 - 11:46 AM
#9
true...have you ever tried the SE Sport hydrofoil on a 40hp or similar? Supposedly it gives faster planing with a lower planing speed.
Posted by John Fyke on 07/23/10 - 12:04 PM
#10
I personally am not a fan of Hydrofoils. If your boat is mounted, and propped right you won't need it.
Posted by Joe Kriz on 07/23/10 - 12:06 PM
#11
Sorry,
I didn't mean to confuse you on the pitch sizes for different engines.
My 15 pitch was on a 70hp motor...
Your 14 pitch sounds about right for your WOT speed of 6,000 RPM's if that is what your manual calls for redline....
For a better hole shot, you would want to try a 13 pitch prop.
But don't buy one, try one out first....
I am not found of hydrofoils and I have tried one in the past.
Before I would resort to a hydrofoil I would make sure the engine height is set properly.
Posted by noleman on 07/23/10 - 12:21 PM
#12
Thanks for the info. It is set on the lowest(height) of 5 positions(top hole). How do I know which hole is correct?
Posted by John Fyke on 07/23/10 - 1:08 PM
#13
Raise your motor at least two holes. Then see how the boat performs. Typically your cavitation plate at WOT should be just under the water for top performance.
Posted by noleman on 07/23/10 - 1:27 PM
#14
thanks, is there an easy DIY way to accomplish this? I don't have a motor stand.
Posted by John Fyke on 07/23/10 - 1:33 PM
#15
If you have a jack you can raise it without dismanteing. It will take two people. One to jack and one to steady the motor.
Posted by Shrimpy on 07/24/10 - 5:04 AM
#16
That is a factory rigged boat (I have a 2009 Supersport rigged the same way) The factory knows what it is doing and tests a whole lot more than all of us combined.
It comes with an Alum 14 pitch prop with cup.
I would not mess with motor height on this boat as see above (The factory knows and tests)
Mine had a walmart fin on it when I bought it. It jumped up on top pretty good with 2 people and a cooler.
I removed the fin after one test trip as I am not a fan of them either. Have not had a chance to test again without the fin, but will be happy to report back (before you drill holes in your plate)
If your turning 6000 that is the max RPM for that motor.
The thing you have to remember is to trim with your speedo, not your tach.
At any given throttle position (not tach reading) you should trim for max speed at that throttle position.
A speedo (or GPS)is much more important than a tach.
The tach is only there to keep you from blowing up the moter. (New motors have a rev limiter so .....) and to get a reading at full throttle when the boat is trimmed to max speed so you can pick the right prop.
Having said that, if you are running heavy (3 -4 people you may need a 12 or 13 pitch. Also if your willing to give up a bit of top speed a 4 blade prop will create more stern lift (read better hole shot)
Edited by Shrimpy on 07/24/10 - 5:06 AM
Posted by noleman on 07/24/10 - 5:31 AM
#17
thanks shrimpy....I don't have a gps yet. I would like to know your thoughts again with the foil. I would consider the 4 blade prop, even though top end drops but who runs WOT anyway?
Posted by Ric232 on 07/27/10 - 7:09 PM
#18
I don't agree that the factory necessarily knows best, especially if the motor is mounted all the way down. My '08 130 had the motor mounted in the middle hole. It ran fine but I raised the motor one hole (so it's now one hole from the highest position) and it runs better. But in your case, even if you raise the motor to a more appropriate height, I don't think it's going to improve your holeshot (your main complaint) one bit. Everything else should get better.