New Prop for 120 Looper

biglurr54

Petty Officer 1st Class
Joined
Feb 14, 2011
Messages
234
I have a 18 ft aluminum boat with a Evinrude 120 looper. The dry boat weight is 1200 lbs. I have two mangled props that came with the boat. one 13x19 and one 14x17. I was able to straighten the 13x19 out enough to use it. It is in really rough shape though. I am interested in hole shot and pulling power as i use the boat mainly for putting around the lake and on the weekends we do some skiing and wake boarding. I am thinking of giving a 4 blade prop a try. Im not sure of size. I plan to talk to the local marina about it but he can get greedy so I like to have as much knowledge before i go to him. What size would be best for a three blade prop and what would be the best size for a 4 blade prop.
 

biglurr54

Petty Officer 1st Class
Joined
Feb 14, 2011
Messages
234
Re: New Prop for 120 Looper

I went in to the Dealer and he told me i had no choice the only thing he could sell me is a 17p brand new michigan wheel which I would need a hub kit with. I told him I would like to try some props and that the prop on it now is 19p. I knew he had boxes of used props in good shape sitting on the floor. I started to dig through then and he yelled at me and said I wouldnt find what i need in there and that they are all odd props. I kept preasuring him to let me look. Finally he started to dig with me. I wanted to relieve the engine as it is old and I never go full throttle. He said he could only sell me a 17 or 19 pitch. He would explain which would help unload the engine. Finally I found a prop that still had a sticker on it that was the exact same as my prop thats on the motor now. 13x19. I asked him how much and he said $40. On the way out he said he was glad the box was a little lighter and he doesn't know what he's going to do with all the props. I could kill him. If i am correct a 14x17 would unload the engine and give it a better hole shot over a 13x19 right?
 
Joined
Feb 17, 2012
Messages
2,906
Re: New Prop for 120 Looper

19 is a good starting point if you decied that getting up on plane is worth a lower top speed then get a 17 when you can. I have the 120 and i have both 17 and 19 and change between them depending on what im doing plus its a great idea to carry a spare prop.

gps and rpm at wot with the motor trimmed correctly will allow you to calculate prop slip

then for fun theres ss, alluminum, cupped, 4 blade, drilled, etc etc
 
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