19-6 boat has trouble out of hole

[91 boat owner]

i have a 1991 ski boat with a 4.3 Mercruiser, it has a 3 blade 19P prop. I can only go 35 MPH at about 3600 RPM, wondering if i change to a 17P prop, will it help, and if i add the whale tail to the outdrive(or if someone can tell me the correct name for the attactiment, so i dont look like a dumb *** asking a shop for it that woould be great) any info would be great

 

[pinecrestwoods]

Re: 19-6 boat has trouble out of hole

I think I can hear the calculators clicking away.

Without any fancy analysis.... your "35mph" at 3600 rpm doesn't seem bad. I would think that's a very comfortable cruising speed. Remember, you've still got 800 or a shade more rpm. Or.... on second thought, did you mean to say 4600rpm (WideOpenThrottle)? If you're maxing at "35mph" you could prop for a tad more speed, BUT your post title says "trouble out of the hole." Which is it?.... are you looking for more "get up and go" or more "top end"?

Also, a boat speedometer is a mere suggestion of how fast you are truly going.

Also also- what boat are we talking about, specifically?

 

[pinecrestwoods]

Re: 19-6 boat has trouble out of hole

:redface:

Okay, Bubba, your interpretation makes more sense than mine. I just got all excited to post something, and didn't think it through.... I'm sure you understand.

Are there any other symptoms or behavioral changes?

Did it used to go faster?

 

[Bondo]

Re: 19-6 boat has trouble out of hole

I just got all excited to post something, and didn't think it through.... I'm sure you understand.

Ayuh,.... You'll get over it,.... Someday...

I can only go 35 MPH at about 3600 RPM,

Ayuh,...When was the last time this tub was given a Full, Complete Tune Up,+ Service,..??

Btw,... EFI or Carbed,..?? Which Carb,..??
What Drive,..??

I think your motor is Sick, rather than the prop to Big...
Unless of course the Hull has other Problems.....