1975 15hp johnson

[nitro21slck]

hello i was wondering if the fuel line for a 1975 hohnson 15hp had one or two lines? is there a way to change my long shaft to a short shaft? if so how?
thanks

 

[tx1961whaler]

Re: 1975 15hp johnson

Welcome to iBoats!
The motor has a single fuel line, not the double line.
You can change from a long to a short shaft, but it involves getting a new driveshaft and shorter water tubes. The easiest way is to get a lower end off of a donor short shaft model.

An easier way (if possible) is to use a jack plate to raise the mounting point on the transom up 4 inches or so.

 

[tashasdaddy]

Re: 1975 15hp johnson

you can either do a transom elevator or a jack plate. we are talking about a 10 hp, so a transom elevator is the right solution. it is taking 4 pieces of 1 1/4 inch aluminum angle, sold at home depot near the screws and nails. you put a 2x6 on top of your transom thru bolt it with 4 bolts, then thru bolt thru the transom. i would use 18 inch pieces of aluminum angle. so you need 4 pieces of angle and 10 3/8 bolts& nuts, 20 washers 10 lock washers. get it mounted set the motor and go boating, safely.

 

[Rick.]

Re: 1975 15hp johnson

Replacing the leg is probably the cheapest option for sure. You have a good situation cause you can get one that has bad gears for cheap and you have multiple years that will fit and 9.9 and 15 legs are the same. Good luck. Rick.

 

[samo_ott]

Re: 1975 15hp johnson

you can either do a transom elevator or a jack plate. we are talking about a 10 hp, so a transom elevator is the right solution. it is taking 4 pieces of 1 1/4 inch aluminum angle, sold at home depot near the screws and nails. you put a 2x6 on top of your transom thru bolt it with 4 bolts, then thru bolt thru the transom. i would use 18 inch pieces of aluminum angle. so you need 4 pieces of angle and 10 3/8 bolts& nuts, 20 washers 10 lock washers. get it mounted set the motor and go boating, safely.

I would change it slightly. I built a small boat last year and used a 2x8 for a transom but it cracked along the grain (I had a 10hp on it also). They are not that strong. So I ended up laminating 1/4" plywood on both sides for strength. If I did it again I would use a piece of LVL (for laminated beams) or make my own by laminating 3 pieces of 3/4" plywood together. As plywood is cross grained it is much stronger than a 2"x whatever.