1975 Johnson 9.9/15 20inch shaft

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cyberflexx

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Hey guys,

Sorry I had been gone for a while, but life gets in the way ( i have 3 kids now..:) )but anyway..
I am going to start building up a new Tracker 1436 into a mini bassboat. My motor is a 1975 Johnson 9.9 converted to a 15hp with a 20inch shaft. How hard is it to convert this to a short shaft and what parts do I need to purchase for the conversion? The Tracker 1436 will need a mini jacker jackplate installed to lift the motor up 5 inches or so if I want to keep the motor as is. If i decide to go that route, will that cause the boat to be off balance? I plan to put decking in the 1436 as well..

Any help would be great!
 
Personally, I would go with the mini jacker. Shortening the shaft depends on a couple things. On some motors, the drive and shift shaft had connectors, and a 5 inch extension. On these, the only thing you have to do is disassemble, remove the connectors, cut down the water hoses, and bolt back together, minus the 5 inch extension housing. On the rest, however, a new driveshaft and shift rod will be needed. All that I have messed with have been the latter type, and even if you found the correct drive and shift shaft, you would have to do a full lower unit disassembly to swap.

See if you can even out trade for a short shaft 15, as some people need a long shaft and have a short shaft. Or, just go with the mini jacker, or make your own.
 
Will the mini jacker cause the boat to be out of balance and center of gravity be off? Will it make the boat not go as fast as a shot shaft would? I just dont want the boat to be unstable.
 
Shouldn't have much effect. All it is doing is setting the motor back 5 inches. Especially seeing you are decking, I don't see that as a problem. Ideally, you may want to mount it 1 inch higher, so you have 6 inches of raise, since you have setback, but you won't know that until after you start messing with it.

If you make your own, you can do as some member do, and fabricate it to not have any setback. That will provide no balance issues whatsoever, unless your boat is so stern heavy that it can't take the extra 5 pounds the long shaft motor weighs over the short one.
 
I have done this to a couple of motors & isn't a big deal.The drive shaft is the only thing you have to buy.They can go from $35 to $75.The shift shaft you can cut & regroove for the connecting bolt.Just take apart,remove spacer,cut shift rod,& water tube.Some water tubes have an extension that you just remove.Pretty straight forward.That's a good motor you have there.I have the same one except a year newer.Don't forget to put a new impeller in when you do this
 
I think me and a friend are going to make a jackplate. we found some metal scrap shaped like this (top view of metal peice) [___] that is the exact shape of a regular jackplate and the perfect width for my motor. We will need to do cut the metal down to length and drill holes in it, put a little wood in it so the motor can be mounted.
 
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