floatingisboating
Recruit
- Joined
- May 31, 2011
- Messages
- 4
I am looking to replace the prop on a 1989 20' Godfrey Marine Aquapatio pontoon boat. The engine is a 1989 Mariner 9.9hp 2 stroke, 2 cycle engine with 20" shaft. Current propeller is a 9" diameter and a pitch of 9". Boat weighs in a 2100lbs dry with no gear.
It desperately needs a new one for two reasons. The edges are heavily worn from running through gravel and twigs/trees. The reservoir is shallow is many areas
The second reason is the service manual says the RPM range for the engine is 5-6K @ WOT. I got a tach reading of 4200 RPM. Boat was bought new and then stored after 5 years of use. It returned to service last year so the internals of the engine aren't too heavily worn.
Looking through my Quicksilver guides from 89' for boats up to 1600lbs use a 9x9" prop. For boats 2100lb and heavier use a 9x7" . . . but I'm having trouble finding a prop finder that shows this older engine.
I can't clear anything larger than a 9 1/4" diameter. Also would the 7" pitch raise the RPMS up to were I need them? What do you guys recommend?
It desperately needs a new one for two reasons. The edges are heavily worn from running through gravel and twigs/trees. The reservoir is shallow is many areas
The second reason is the service manual says the RPM range for the engine is 5-6K @ WOT. I got a tach reading of 4200 RPM. Boat was bought new and then stored after 5 years of use. It returned to service last year so the internals of the engine aren't too heavily worn.
Looking through my Quicksilver guides from 89' for boats up to 1600lbs use a 9x9" prop. For boats 2100lb and heavier use a 9x7" . . . but I'm having trouble finding a prop finder that shows this older engine.
I can't clear anything larger than a 9 1/4" diameter. Also would the 7" pitch raise the RPMS up to were I need them? What do you guys recommend?