need advice for 1976 johnson

[jamesgduratech]

i have bought a 1976 johnson 15 hp for my little 12.9 ft aluminum runabout. it goes along pretty good for a first boat... but i want a little
more omph. and it NEEDS to be legal.it goes about 25 mph now but i was wondering if omc made racing props and stuff for that size.

I NEED SOME SPEED!

 

[Faztbullet]

Re: need advice for 1976 johnson

Yes they make racing parts for you size engine but you will get better performance by setting it up correctly. You can get a stainless steel prop for your engine by Solas.The largerst is a 9/14 x 11 pitch part number#2121-093-11

 

[jamesgduratech]

Re: need advice for 1976 johnson

thanks sooooooooooo much

 

[fireman57]

Re: need advice for 1976 johnson

25mph sounds awful fast for a 13ft boat. Any faster and I think you might be risking safety.

 

[jamesgduratech]

Re: need advice for 1976 johnson

thanks for the opinion! i think it might work out because the boat has LOTs of heavy wood inside and i drive from the front. but ill save the old prop just in case its to fast.

 

[nwcove]

Re: need advice for 1976 johnson

if you are maxing out the rpms, more pitch could help, but why the need for speed? things can go wrong really fast in a boat that small..or even larger at speeds lower than you can imagine! ( op must still be young, and not lost that feeling of invincibility yet!)

 

[jamesgduratech]

Re: need advice for 1976 johnson

i don't really mean speed i mean just a little more powerful so i can still go kinda fast with more people in the boat. i also need to be able to just get up and go quicker. i don't want to go over 32 mph because then it would be very dangerous.

 

[AEROCOOK]

Re: need advice for 1976 johnson

i don't really mean speed i mean just a little more powerful so i can still go kinda fast with more people in the boat. i also need to be able to just get up and go quicker. i don't want to go over 32 mph because then it would be very dangerous.

If you want to be able to go fast with the boat loaded and you also want to get a better hole shot, you will need a prop with less pitch. This will almost certainly reduce your current top end speed, even with just you in the boat. It's all about setting up the boat / motor package to operate well under your normal operating conditions.
This is all assuming that the motor is properly adjusted and tuned.

 

[nwcove]

Re: need advice for 1976 johnson

its kinda hard to have the best of both worlds.....hole shot, and speed.....low pitch, is good hole shot, high pitch is good speed. how many people are you putting in a 13 foot boat??????

 

[jamesgduratech]

Re: need advice for 1976 johnson

its kinda hard to have the best of both worlds.....hole shot, and speed.....low pitch, is good hole shot, high pitch is good speed. how many people are you putting in a 13 foot boat??????

usualy 1-4 people in the boat.

 

[nwcove]

Re: need advice for 1976 johnson

four people in that boat, at 20+mph, is getting kinda scary! (maybe im just old )

 

[jamesgduratech]

Re: need advice for 1976 johnson

four people in that boat, at 20+mph, is getting kinda scary! (maybe im just old )

your not old!