1991 Yamaha 20hp 2 stroke - Shift Linkage/Lower unit

[SpaceNoodz]

I have a 1991 Yamaha 20hp 2 stroke short shaft, (6A9 S 017845 - C20MSHP). I am looking for tips/tricks on removing/reassembling the lower unit with the shift linkages. I heard they can be a disaster if not done properly so I am hoping someone can point me in the right direction so I don't have to take this thing apart 14 times lol...

Thanks a lot.

[robert graham]

Put motor shift in neutral, then drop lower unit to do your work….being sure not to move the shifter linkage control or the shifter on the lower unit…..then when you reassemble the unit it’ll be right back where you started…

[boscoe99]

I vote for shifting the motor into reverse. To gain better access to the coupling and jam nut. Barely loosen the jam nut. Then turn the coupling nut until the two shaft separate. Remove the lower unit. Don't mess with any shifting parts.

Upon reinstalling the lower unit, turn the coupling nut downward until it just about reaches the jam nut. Hold the coupling nut from turning while tightening the jam nut against the coupling nut.

[robert graham]

Boscoe is dead right about that….I was referring to the splined shift shaft on my old 90C Yamaha…

[panasonic]

I vote for shifting the motor into reverse. To gain better access to the coupling and jam nut. Barely loosen the jam nut. Then turn the coupling nut until the two shaft separate. Remove the lower unit. Don't mess with any shifting parts.

Upon reinstalling the lower unit, turn the coupling nut downward until it just about reaches the jam nut. Hold the coupling nut from turning while tightening the jam nut against the coupling nut.

I vote that way as well...cause that how's its done.lol
I would add spray the joint down with some WD40 or whatever you got. The bronze coupler nut on the stianless rods can be trouble.