Bass Fishing Forum - Westernbass.com

I just put a remanufactured 115 merc on my 18' champ, runs great but way to many rpms'. Has a 3 blade 19 pitch on it, any thoughts. btw, am at altitude

That is a tough one. Did the motor originally ship with a stock propeller? If so what size was it? I might start there if possible.

I have a 115 Opti, and run a 3 blade Laser2 20P. I originally had a 4 blade 19 on it, but it wouldn't get on plane up at 3500', and my Merc. mechanic recommended the prop switch.
Altitude is a tricky deal. It robs horse power, and, for smaller motors, that's critical.
If there's a factory authorized Mercury dealer near you, or a prop shop, call them and ask them what they recommend for your boat/motor.
If not, I would call Mercury, and talk to their techs. about where you live, which boat you have, and what they recommend.

More info would help.

What altitude?

What rpm/speed do you run? What is the max rpm recommended for your motor?

Does the boat have a jack plate? Prop to pad measurement?

I used to own a 17' champion with 115 and i believe it had a 19 pitch 3 blade laser II mercury prop. The rpm's would exceed the recommended max only if over trimmed.

I would try all the props I could get my hands on. I had good luck with 19 pitch high 5s on the boats I ran a 115 and a 90 on . If you don't have a jackplate, the 3 blade props seem to vent and run high rpm trying to lift the boat front. A high 5 bites well and will run with much more trim.

Thanks for the info. I'm ay 5200 feet, ran a 4blade 23 on the 150 I had before, was great. Have a 4 blade 20 gonna try next