Diablo w/ 4.3 has trouble planeing, Prop size?.
 

I have a Diablo with a Alpha One 4.3 v6 that is a great little boat when its just my lightweight girlfriend and I.
When we add 3 young teenagers it barely gets on a plane, I have to have 2 off the kids get in front.
The prop is a quicksilver stainless with 21 pitch.
A local dealer thinks I should go to a 19 pitch but wants me to record rpm numbers first which I havent done.

Does anyone have any suggestions as to what prop would work based on your experience?
Thanks

Rick in Austin

Re: Diablo w/ 4.3 has trouble planeing, Prop size?.
 

I think its a 1993 but am unsure without looking at my manuals, can you guys tell by this pic?

Re: Diablo w/ 4.3 has trouble planeing, Prop size?.
 

funny, I see no boat in that pic......

but I can understand your issue. My 1992 2000Z with the 5.0L has the same issue planing off. I don't know my prop's pitch, but I assume if I were to change it, it would make a difference.

Re: Diablo w/ 4.3 has trouble planeing, Prop size?.
 

Uhhh, what was the question again? yeah, she looks like an early 90's model :eek_animated:



There's a couple threads going in the props forum that might help. But generally a lower pitch will get you out of the hole quicker. definitely record your WOT rpm before going down though. If you're already running at max rpm, you might have go to a 4 blade or something bigger to help keep the rpm's down with the lower pitch.

Re: Diablo w/ 4.3 has trouble planeing, Prop size?.
 

[QUOTE=blockp;14716]Uhhh, what was the question again? yeah, she looks like an early 90's model :eek_animated:

Early 90's??? I'd say late 20's at best.

:tt1:

I would definately go Stainless on the prop, whatever the pitch. Worth the money. Good luck

Re: Diablo w/ 4.3 has trouble planeing, Prop size?.
 

She looks older than 16. I think we'll need more pictures to be sure... ;)

x2 on getting the numbers before you re-prop. Obtain your WOT rpm, your top speed (gps would be best). If you know (or can find out) your drive ratio and the approximate weight of your boat (93 brochure lists 2200# for the Diablo), you can use the mercury prop calculator to see what prop would be a good fit to your boat.

Mercury Prop selector

Re: Diablo w/ 4.3 has trouble planeing, Prop size?.
 

Thanks guys, good advice and I will sure follow it.
Lauren will also appreciate that she looks like she is in her late 20s!
She just turned 32 and its killin her :)
I have been teaching her to fly and she has become a darn good pilot, now that the summer is here we are putting the little Diablo to very good use.
Here are some pics of the boat, Lauren and the planes.

http://www.flickr.com/photos/38883018@N07/

Re: Diablo w/ 4.3 has trouble planeing, Prop size?.
 

Today is my 39th birthday, so tell her to just be happy that she will never be as old as me!

Re: Diablo w/ 4.3 has trouble planeing, Prop size?.
 

32??

I've got socks older than that!!

Smart tabs first, (cheaper than a new prop), if that doesn't change anything, (bet it will), then try a 19 SS prop.

Re: Diablo w/ 4.3 has trouble planeing, Prop size?.
 

Smart Tabs will definitely help, but let's get these numbers before anything (especially the girlfriend's, but understood if they're missing from your response:yes_grin:)!!

The only way to really "tune" in on a correct prop size suggestion is to know the current max speed, RPM, gear ratio, etc. as already pointed out. Another factor - what's the condition of the current prop?

21 pitch is a tad bit high for the 4.3, but definitely doable. Does your boat "growl" at all while idleing or turning? That could be the gimbal bearing which robs power when it goes bad. Also, what 4.3 is it - standard or LX (what horsepower)?