Tried new prop, still not happy with hole shot/acceleration, new specs:

[Boester]

SPECS:

2007 Maxum 1800 SR3

4.3L MPI Alpha 1
21p Revolution 4
WOT: 4500 RPM @ 46 (MPH) GPS (49 boat speedo)
Half tank of fuel (apx 12-14 gal)
Light load - just me and basic gear

So this boat had always been a dog getting out of the water and up to a plane, and worse so trying to pull a single skier or tube when I running with the orig 24p Bravo 1 prop. No hole shot what so ever...

Working with a local prop shop, he recommended the the Revolution 4 (specs noted above). Running it the other day, I still have no hole shot and it still took what seems forever to get the boat on a plane. I think I lost a few MPH switching from the Bravo 1 to the Rev 4, and had not previously checked the WOT RPM's.

I really want this boat to get up and going quicker and am looking for suggestions. I don't mind giving up some top end MPH and believe the WOT should be 4400-4800 on this motor. Thanks in advance for your input.

 

[theBrownskull]

Re: Tried new prop, still not happy with hole shot/acceleration, new specs:

Boester,

Try a 19 pitch basic Mercury Vengeance prop. I put this on my prior boat, Starcraft 1810 SS with a 190 hp V6, and it ripped. It had WOT RPM's of 4800 and would pull your arms out of the socket if I canned it.

 

[Boester]

Re: Tried new prop, still not happy with hole shot/acceleration, new specs:

Bump... Any input?

 

[steelespike]

Re: Tried new prop, still not happy with hole shot/acceleration, new specs:

Would be interesting to see the wot rpm and speed with the 24.I would expect the 24 to produce poor hole shot.
I would expect you to lose some top end going to the 4 blade.
What is the actual time to plane? My opinion it should pop on plane pretty easily.
Does the boat seem to respond to up trim?
Are you sure the trim is going all the way down for hole shot?
Don't assume because it is relatively young all is right.
Check that the throttle opens all the way.
Is the bottom clean and smooth?
While the timing is probably electronic be sure it is set right and advances as it should.

 

[Tail_Gunner]

Re: Tried new prop, still not happy with hole shot/acceleration, new specs:

Something is not right...(24 pitch)...Post your gearing plz other than that the performance of the 21 rev 4 sounds right. In a 4 blade... pending gearing..... a 20 is about as tall as you want to go or can go. If you have 1.6 gearing your repost is spot on where it should be with a 21

 

[Boester]

Re: Tried new prop, still not happy with hole shot/acceleration, new specs:

Sorry for delay and thanks for the replies.

The gear ratio is 1.6. Trim is fully operational and trimming up does have an effect once planing. I'd also say it takes a good 10 secs to get up on plane. Throttle appears to operate fully.

Next thing would be to consider staying with a 4 blade and dropping down a bit more or trying a 21 pitch 5 blade such as the High Five. Thought?

 

[Tail_Gunner]

Re: Tried new prop, still not happy with hole shot/acceleration, new specs:

19 pitch 4 blade solas or a 20p 3 blade solas..That will get your rpm up as well as performance.

 

[fishrdan]

Re: Tried new prop, still not happy with hole shot/acceleration, new specs:

Working with a local prop shop, he recommended the the Revolution 4 (specs noted above).

Go back to the prop shop and let them know the Rev 4 prop isn't performing well, low RPM (4500) and poor hole shot. Hopefully they will swap props to something better....

TG's recommendation of a 19P 4 blade sounds about right.

 

[Boester]

Re: Tried new prop, still not happy with hole shot/acceleration, new specs:

Thanks TG and Fisherdan... 19p will be my next. I'll let you know shortly.

 

[dvtran]

Re: Tried new prop, still not happy with hole shot/acceleration, new specs:

I went with a four blade 19 pitch and lost about 8 mph on the top end but get up out of the hole four times quicker. Pulling a 200 pound wake boarder is much easier on the rider. I'm running about 4800 rpm at 49 mph.