Johnson 1957 18hp

[mando81]

maybe you guys can help me I'm told I can change out the lower unit from a 56 10hp Johnson to my 18hp, this is the deal I'm pretty sure the lower unit is toast when I take it out even if I change the lower unit oil right before the trip by the time I hit the ramp there is milky white oil leaking out of it most likely just a seal but when I'm driving the boat slow it runs fine and when I try to open it up the motor revs very high as if it's coming out of gear could this be fixed I'm getting a good deal on two 10 1956 models one is a good runner and the other runs too but is mostly a parts motor will the lower units be compatible and help please

 

[mando81]

Re: Johnson 1957 18hp

My 18hp model number is FD-11
Not sure the model number on the 10 hp but I'm told it's a 1956

 

[ultra353]

Re: Johnson 1957 18hp

The `56 10 hp uses the 5 bolt LU so it should bolt right on. A LU seal kit is about $20 if you want to fix the leaks.
IF its revving and not moving at higher power than most likely its a spun hub in the prop- $40 +/- to have it rehubbed. If it feels like your hitting a log underwater than most likely its a worn clutch dog. Or a smaller possibilty is the shift linkage is out of adjustment.

 

[1946Zephyr]

Re: Johnson 1957 18hp

When you tear it down for a rebuild, you can flip the clutch dog over, or get another one.

 

[kfa4303]

Re: Johnson 1957 18hp

HI mando81. Welcome to iboats. Cool old motors you got there. Sounds like you are slipping out of gear due to a worn clutch dog. If you need a new one check ebay, aomci.org, marineengine.com, or right here in the forums. Here are some great links to help you give the motor a tune up from top to bottom along with the parts catalogs for both motor in question so you can cross-reference the part numbers. Good luck. Keep us posted.

http://www.marineengine.com/parts/v...ntage-evinrude-johnson/376747/37674700001.htm

http://www.marineengine.com/parts/v...ntage-evinrude-johnson/377022/37702200001.htm

http://www.leeroysramblings.com/johnson_E-FD_15_18hp.html

http://www.duckworksmagazine.com/06/columns/max/index6.htm

 

[mando81]

Re: Johnson 1957 18hp

I will thanks a lot

 

[mando81]

Re: Johnson 1957 18hp

It's only when I try to go full speed at a low speed it runs fine as soon as I give it gas the motor revs boat won't move I pull back on throttle and give it gas slowly it goes fine motor does tump at all just revs high

 

[mando81]

Re: Johnson 1957 18hp

Motor does not tump at all just revs high

 

[kfa4303]

Re: Johnson 1957 18hp

Hello again mando. If it feels like you're hitting a submerged object, it's probably the clutch dog. However, if it simply over revs, you probably have a spun hub in your prop in which case you'll need to remove the prop and scribe a line across the back along all surfaces, then take the motor back out on the water and get it up to speed, then remove the prop again to inspect the prop. If the line is no longer level, then your hub is bad. Unfortunately, you can't fix it yourself. You'll need to get a new/used prop, or have it rehubbed at a prop shop.

 

[mando81]

Re: Johnson 1957 18hp

Ok do I make the line even with the key hole to see if prop moves from hub I'm new to do it yourself methods

 

[RSchendel]

Re: Johnson 1957 18hp

Make a mark on the brass inner hub and on the inner edge of the prop. I used a sharpie to test mine.

 

[mando81]

Re: Johnson 1957 18hp

Ok I'll do that and post my findings thanks a lot you guys have been great