another prop recommendation

[tschamp20]

hey fellers,so ive been breaking in my newly rebuilt 1973 johnson 115 but the most rpm's i can get out of it is 4800.no trim & tilt but it is set at the highest locked position.
i currently have a 13 1/2 x 19 pitch prop.
what prop would you recommend to get the proper rpm?
motor calls for 4500-5500 but i thought i read something about exceeding that. any help is appreciated.

 

[steelespike]

Re: another prop recommendation

What boat are you running it on? Give some detail.Aluminum or stainless steel prop?You may need to raise the motor vertically.
Where is the antivent plate in relation with the bottom of the boat?
What is your speed.You will want to optimize your setup before making a decision on a prop.

 

[tschamp20]

Re: another prop recommendation

the boat is a 17' fiberglass trihull.current prop is aluminum.the anti-cavitation plate is perfectly inline w/ the bottom of the hull.speed unknown havent been able to splerdge for a speedometer.judging by the FAQ article about prop selection i would think a 15 pitch. but unsure about the diameter.

 

[tschamp20]

Re: another prop recommendation

bump

 

[Dhadley]

Re: another prop recommendation

You're not going to have a lot of choice about diameter but generally it'll be 13 1/4". A 15 seems a bit small but it'll pull the r's. The plate being even is a little low but good enough. Think about adding trim. The CMC (Cook Manufacturing) trim unit works real well.