Need a new prop. And a little help on size.

[10 FOOT INVADER]

I managed to break all three of my props this season. We boat on lanier in ga and the water is low. My current size 3 blade prop is a 14.5 x 19. aluminum This will hit about 42 mph gps at about 5200 rpm. Rpms to high, need to prop for around 4600 rpm. Engine is a 5.0l 2bbL carb in a 94 20foot monterey. Also broke a 4 bladed aluminum prop. I have a prop# but not the size. prop# 48-83435 c-13. Also on the 4 blade prop is gp25904. The 4 bladed prop was also out of rpm range. Speed the same around 42mph gps but the out of the hole shot was most excellant. Thanks for the help.

 

[inPursuit]

Re: Need a new prop. And a little help on size.

It sounds like you need to increase the pitch of your prop. If you are currently running a 19 move up to a 21 pitch in the three blade and see if that brings you down enough. If that is not enough you can always try a 23 pitch. Once you find the right three blade you should run a 4 blade that is smaller in pitch. For instance if you run a 23 3-blade a 21 4-blade should perform correctly. Are you breaking your props because you are hitting stuff or because you are throwing blades?

 

[10 FOOT INVADER]

Re: Need a new prop. And a little help on size.

We boat in lake lanier ga and the water is very low. I think the prop at times hits soft sand when we beach. Also i must confess that we have hit several rocks just below the surface. With new props we will be a whole lot more carefull. I will be ordering the 21 pitch 3 blade then if works out the 4 blade. Thanks for the info.

 

[stubbsboogie]

Re: Need a new prop. And a little help on size.

Also you might consider switching to Stainless steel props. They are much more durable and will handle dings and ricks better. Expensive but in most cses worth the money. I am in a similar dilema need a different prop but am afraid to go to alum cause of rock and sand.
I am not an expert in props but I do agree with inPursuit probably move up in pitch and that should get the rpms where you need them.
Good luck

 

[steelespike]

Re: Need a new prop. And a little help on size.

I believe stainless props are cost effective in soft contacts,sand,mud,stumps etc.Not sure about rocks etc.I'm sure they would hold up better than Al. but whether you could avoid repair I don't know.Maybe someone has personal experience.

 

[Bondo]

Re: Need a new prop. And a little help on size.

Ayuh,...

I'd rather buy 10 Aluminum props a year...

While SSteel props may not Ding as easily,.. They transfer the Impact to the Outdrive...

Aluminum props are Cheap, compared to outdrive Gears,+ Shafts.....

 

[10 FOOT INVADER]

Re: Need a new prop. And a little help on size.

Picked up a new ql series 14.3x21 prop and a hub that had springs. Boat fully loaded and full of play toys for the 4 kids, wow. The boat has a great hole shot and the top end speed has increased to abought 55 mph gps. Could have got more speed out of it playing with the trim but with the kids did not want to push it. Rpms around 4200-4300. Thanks for the prop reccomendations.