prop issue

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milehi
Posts: 304
Joined: Wed Apr 29, 2009 4:32 pm

prop issue

Post by milehi »

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
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Bass hack
Posts: 65
Joined: Wed Sep 09, 2015 8:30 am

Re: prop issue

Post by Bass hack »

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.
mark poulson
Posts: 10370
Joined: Sun May 08, 2005 4:16 am
Location: Antioch, CA

Re: prop issue

Post by mark poulson »

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.
Attitude plus effort equal success
CLEAN AND DRY
Champion Jon
Posts: 369
Joined: Thu Apr 24, 2008 12:59 pm
Location: Roseville, CA

Re: prop issue

Post by Champion Jon »

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.
Rod Martin
Posts: 2819
Joined: Sat May 07, 2005 6:31 pm
Location: Holiday,Fl.

Re: prop issue

Post by Rod Martin »

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.
TR177 Ranger/ Mercury/Lowrance/ Ghost TM
milehi
Posts: 304
Joined: Wed Apr 29, 2009 4:32 pm

Re: prop issue

Post by milehi »

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
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