Caddy_Kid
Petty Officer 2nd Class
- Joined
- Nov 18, 2005
- Messages
- 113
I have a 1965 Mercury inline 6 100 HP outboard on my 16' Stevens runabout. First time I took it to the lake it did fine, but could have used another 400 RPM's or so at WOT. So I went from the 17 pitch that came with the boat to a new 15 pitch Piranha (http://www.piranha.com/) propeller after reading that they are lighter, faster, easier to change the pitch and/or blades and finding that the price was quite good.
Had to modify the motor trim tab because the new blades have alot more rearward rake from the hub to the tip than the origional prop. Not a big deal, just cut out a 1/2" triangle and filed the edges.
Took it to the lake, and it ran fine, but the boat lost 10+ MPH and actually lost RPM's instead of gaining them.
Ok, traded the 15 pitch blades in on some 17 pitch blades (really easy, up to 90 days from purchase just return the old blades, pay shipping, and they give you new blades to try a different pitch and/or diameter). Put them on the boat and it did even worse, 2000 RPM drop and no speed at all. Put the origional prop back on and it was back up to 4500 RPM WOT and nearly 40 MPH.
So the Piranha goes back on Monday. I know that they work great with newer motors, but my old one just needs the old style propeller. I like their product, someone actually answers the phone when you call, not a prompt, and nice people to work with. They are quite a bit lighter than aluminium, they have a cupped edge, and a lifetime warranty on their hub assemblies. I did notice that when putting the motor in gear, it didnt bog down as much, probably because the prop was lighter. It was also faster to get on plane. If it hadnt dropped my RPM so much, I would have been very happy.
I dont want to scare anyone away from their products, just let anyone that has an older motor know that new style props probably wont work well, composite or otherwise. Thanks.
Had to modify the motor trim tab because the new blades have alot more rearward rake from the hub to the tip than the origional prop. Not a big deal, just cut out a 1/2" triangle and filed the edges.
Took it to the lake, and it ran fine, but the boat lost 10+ MPH and actually lost RPM's instead of gaining them.
Ok, traded the 15 pitch blades in on some 17 pitch blades (really easy, up to 90 days from purchase just return the old blades, pay shipping, and they give you new blades to try a different pitch and/or diameter). Put them on the boat and it did even worse, 2000 RPM drop and no speed at all. Put the origional prop back on and it was back up to 4500 RPM WOT and nearly 40 MPH.
So the Piranha goes back on Monday. I know that they work great with newer motors, but my old one just needs the old style propeller. I like their product, someone actually answers the phone when you call, not a prompt, and nice people to work with. They are quite a bit lighter than aluminium, they have a cupped edge, and a lifetime warranty on their hub assemblies. I did notice that when putting the motor in gear, it didnt bog down as much, probably because the prop was lighter. It was also faster to get on plane. If it hadnt dropped my RPM so much, I would have been very happy.
I dont want to scare anyone away from their products, just let anyone that has an older motor know that new style props probably wont work well, composite or otherwise. Thanks.