9.9 Johnson ... or is it? But it has a transmission problem or something.. Help

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Timberwolf17044

Seaman
Joined
Mar 20, 2011
Messages
53
I recently purchased what I assumed was a 1979 Johnson 9.9 Long Shaft. The seller indicated to me that he could not get it to run and I bought it as is for $50.00. Once home I began with a brief inspection and an attempt to start the motor. This particular motor has an electric start. I found that with a bit of fuel squirted into the carb I could get it to fire. I disassembled the carburetor and soaked it overnight in cleaner. Once reinstalled it would fire better but still wouldn't run. Further investigation found a faulty fuel pump. With a new fuel pump and some tweaking I finally got the motor to purr like a kitten while in a barrel in my garage. Forward and reverse seemed fine, water pump seemed fine. Fast forward to today, the first chance I've had to actually put it on the boat and test it on the water. FYI I tested it on a river with rather strong current on a 12 ft fiberglass boat designed for a short shaft motor. I modified the transom to raise the motor to the proper height. So anyhow, I started up the river, going slow at first feeling the motor out all seemed well. After a couple minutes and feeling more comfortable I opened it up further, finally to wide open the boat sailed along quite smoothly almost to a plane. I slowed back down a bit and then began slowly opening it back up only this time the motor picked up rpm but no go. So there is my dilemma, It feels like the transmission is slipping and yet I don't think there is a transmission to speak of is there? Now to add a bit more to this mystery I will add some additional information.
Model: LD-12A
Serial: J2757042
{taken from the tag that is riveted to the transom mount}

J10SELGSE
E5236247
{taken off the freeze plug}

Any guesses as to what the actual size and year this motor might be? Attached are a couple of pictures as well. Thank you in advance for those who can help.


http://www.ajpeachey.com/mark/botamotorsmall.jpg
http://www.ajpeachey.com/mark/botamotorsmall2.jpg
 
P

Patate

Seaman
Joined
Jan 4, 2006
Messages
59
Re: 9.9 Johnson ... or is it? But it has a transmission problem or something.. Help

Sounds like a slipping prop hub, remove prop and, with a marker, trace a line on the hub and prop, start the engine use it and after, remove the prop and check.
 
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steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: 9.9 Johnson ... or is it? But it has a transmission problem or something.. Help

It is a 9.9 likely a 78 or 79.Someone else will have to pin it down. Can't tell for sure but the 9.9 should do about 20 on that boat with an ideal setup and excellent tune.You may have to sit in the middle seat to get it to plane.A tiller extension may be necessary.
If the motor is too high it might be venting.I believe its more likely a spun hub on the prop
you may be able to see the evidence underneath. If you but a water proof line across the hub and run drive it then check the line to tell if its spun.You can have it repaired at a prop shop.
 
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Will Bark

Lieutenant
Joined
Aug 1, 2010
Messages
1,470
Re: 9.9 Johnson ... or is it? But it has a transmission problem or something.. Help

If your "G" is actually a "C" then it is a 1980 9.9 Johnson.
 
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Timberwolf17044

Seaman
Joined
Mar 20, 2011
Messages
53
Re: 9.9 Johnson ... or is it? But it has a transmission problem or something.. Help

Thanks to all the great replies. If weather permits I'm going to try that some evening this week. I'm only a mile away from the river so its not that hard to take it down and try it. I'll let you all know how it works out.
 
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mn808gade

Cadet
Joined
Aug 19, 2010
Messages
6
Re: 9.9 Johnson ... or is it? But it has a transmission problem or something.. Help

1980 sail boat mod. sounds like prop. sail mods. came with smaller pitch prop than stock long shaft-some sail mods=extra 2.5 inches longer than long shaft.
 
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Timberwolf17044

Seaman
Joined
Mar 20, 2011
Messages
53
Re: 9.9 Johnson ... or is it? But it has a transmission problem or something.. Help

Well perhaps I made it even easier. I removed the prop, place a pair of pliers on the protruding shaft, slid the prop down over the spline, held the pliers in one hand and turned the prop with the other. It actually spun the rubber in in hub with very little effort. My next question is going to be should I repair the current prop or just buy a new one? After looking at the prop I determined it to be a 9.5 X 8" pitch 3 blade. It is my understanding that generally speaking on most small semi-v boats 12-14' the standard is a 9" pitch. Most of my boating will be in the river with a fairly strong current so perhaps I should even consider a 4 blade prop? I'd like to hear the general consensus out here from you guru's. However, lest I offend someone by not providing more details let me also say I'm not looking for perfection just a decent running outfit, so I really don't want all the bother of a tach and gps and all that good stuff. I'm sure the exact replacement would work just fine but if the 9" is better suited I'd run with that. Thank you again to all those who offered up their support it is greatly appreciated. I await the replies :)
 
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