Johnson short shaft to long shaft conversion

[FatCapt.]

I have a 1989 Johnson 4hp. that i use for trolling, it is a short shaft model j4rcec. I would like to convert it to a long shaft due to how low powerhead sits to the water.What can I do to convert?

 

[2shallow2sail]

Re: Johnson short shaft to long shaft conversion

You probably will need the leg spacer, the driveshaft, shift linkage, weld an extended water tube on, and probably a couple o rings or seals. Look at the exploded diagrams online and compare long to short. Purchase used parts from ebay or find a junked lonshaft and take the parts you need. If you buy the parts new it will be around $500 with the leg spacer and the driveshaft being the bulk of that. I'd at least find those, then you can buy the rest new if needed.

 

[FatCapt.]

Re: Johnson short shaft to long shaft conversion

Can I just buy a used assembly from the powerhead on down and bolt it on?

 

[2shallow2sail]

Re: Johnson short shaft to long shaft conversion

I don't think so. I think it would be easier to just add the spacer and the new drive shaft. The water tube is one thing you'll need to check, i am not sure how it is attached to the head. You may be able to replace it, if not you'll have to figure out a way to extend it. You just drop the lower unit, bolt on the spacer, swap the drive shaft, extend the tube (or see if you can swap the tube), swap the shift linkage and then re-install. If you haven't changed the impeller in a while you should drop the LU to do that anyways. I converted a OMC15hp from long to short, so same process but mine was easier cuz I just had to cut the water tube.