Too much pitch???

Ammochris

Recruit
Joined
Nov 10, 2018
Messages
2
i recently purchased a 2006 18' Bentley Pontoon with a 50hp Mercury 4 stroke. It's starts and runs great but will not rev over 2500 rems. I have changed the fuel line, plugs, cleaned injectors, new fuel, checked coils. There are no critical or non critical beeps at start up. The prop is a 11 3/4 by 15. I believe WOT is 5500 but I've never had it close to that. It revs higher in reverse. its a 3 blade prop and one blade is bent. I don't know what my speed was, the speed was unhooked. I feel like that is way too much pitch for the motor. The boat revs fine out of gear and in gear with the prop off. Please help!!!!
 

WesNewell

Chief Petty Officer
Joined
Jan 3, 2018
Messages
497
Model 180 weighs ~1500#. You should not be running more than a 9P prop on it. Less than that with a full load.
[h=3]Your setup[/h]
  • Boat type: Pontoon
  • Usage: Overall good performance/0 ft
  • Engine Manufacturer:
    Mercury
  • Engine Type: Outboard
  • Engine Year: 2016
  • Number of Engines: One
  • Engine Family: FourStroke
  • Engine: 50 EFI 4cyl (995cc)
  • Drive / Gear Case: 40-50 HP 3cyl 2-S, 50-60 HP 4cyl 4-S, 1.83 Ratio
[h=3]Details[/h]
  • Calculated Pitch: 8.46
  • Calculated Weight with engine(s): 2,887.00 lbs
  • Calculated Engine RPM: 5,750
  • Calculated Boat Speed: 17.31 mph
 

Ammochris

Recruit
Joined
Nov 10, 2018
Messages
2
From all the calculators and prop sites, I was thinking a 9 would be best. Compression tested good on all cylinders also.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,309
Your bent prop isnt helping you out
 

Bikestdy

Seaman Apprentice
Joined
Feb 20, 2018
Messages
39
Model 180 weighs ~1500#. You should not be running more than a 9P prop on it. Less than that with a full load.
[h=3]Your setup[/h]
  • Boat type: Pontoon
  • Usage: Overall good performance/0 ft
  • Engine Manufacturer:
    Mercury
  • Engine Type: Outboard
  • Engine Year: 2016
  • Number of Engines: One
  • Engine Family: FourStroke
  • Engine: 50 EFI 4cyl (995cc)
  • Drive / Gear Case: 40-50 HP 3cyl 2-S, 50-60 HP 4cyl 4-S, 1.83 Ratio
[h=3]Details[/h]
  • Calculated Pitch: 8.46
  • Calculated Weight with engine(s): 2,887.00 lbs
  • Calculated Engine RPM: 5,750
  • Calculated Boat Speed: 17.31 mph

Just wondering WesNewell this setup form that your posting, is that from a site or is that your own creation? Just wondering where it it's from, i like the layout of it.
 

WesNewell

Chief Petty Officer
Joined
Jan 3, 2018
Messages
497
Most (all?) 50 hp mercury 4s engines have an air intake restricter plate. Removing it will increase the hp to ~60hp.
 
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