Stainless Steel Prop Help 3X14X19

[boatfixer]

e-mail them to me

[email protected]

[Crappie Rage]

Boat fixer you have mail.

[Crappie Rage]

13.25 x 17 four blade stainless prop is on it's way from Indiana. I will let you know if it helps. Thanks for all the help.

[marine_man]

Watch your rpm's with this... I suspect you're going to be very close to the 6k rev limiter with a 17 on this rig..

I presume you weren't able to get your current rpm's with your current prop?

marine_man

[Crappie Rage]

OK put the new prop on and it seemed to pop the boat out of the water faster. Although it was only me and my gal. Thankfully she doesn't add alot of weight to the boat.

When I had it full throttle and messing with the trim, I maxed out at about 6200 RPM. Does this sound normal?

I never ran the boat with the old prop.

[marine_man]

6200 appears to be your WOT RPM (I'd double check that against your operators manual, but that's what I show). Can you hear it hit the rev limiter, or do you only hit 6200 rpm when you're running full throttle and trimmed out?

marine_man

[Crappie Rage]

I could not hear anything that sounded different or like I hit some limitation, but I wasn't trying to hear anything like that either. It just seemed like that was all the faster the boat was going to go. I never looked at the GPS to see how fast I was going but I am sure it was 35, 38 mph which is plenty for me.

On another subject, I would like a trim level gauge on my dash. I am not a mechanic, but am able to take things slow and figure them out. Would I be able to install my own??

[marine_man]

At what condition do you reach 6200? When you're running at full throttle & trimmed out?

marine_man

[hydro]

I thought I'd stay out of this one until you had at least an RPM, and it sounds like you have found a good solution.

Your 2004 Johnson 140 has a gear ratio of 2.38:1 and a max recommended RPM of 6200 so it looks like you are right on target. With nominal 15% slip in the prop your speed calculates to between 35 and 36 MPH and that sounds about right as well. Those numbers combined with a 4 blade prop should give you a great hole shot. Good work!

[Fish&Fowl]

Well I just bought a 2006 Alumacraft Tourney Sport 185 with a 2006 Yamaha 150 4-stroke. With my 14 1/4x19 prop I am getting 43 mph with me, the dog and a full tank of gas trimmed out.

I tested with the same load when I borrowed my friend's 21-pitch stainless and got 47.5 mph. Both props are 3-blade and ran 5400rpm WOT.

Any ideas if this is typical?...it sure seemed to make a big difference. Any recommendations or other info much appreciated!

[marine_man]

What are you seeing for RPM's on your boat?

That sounds pretty typical, although at WOT, and trimmed out you should really be closer to 6000 RPM; but, if you're satisfied with the hole shot you probably can get by with it.

In the future, I'd start a new thread by the way...

marine_man

[hydro]

Sounds pretty typical to me although I would have expected to see the RPM's drop with the 21" prop. Your observed speeds calculate out close at 5400 RPM.