I dropped the lower unit on a 1989 Yamaha V6 to replace the water
pump. While removed I had the mech replace seals and bearings. He
had to apply heat to the lower unit to disassemble (corrosion).
Setting on the bench the transmission shifts fine from forward to
neutral to reverse. Once installed, with the motor running, it is
difficult to shift into forward. Pull the control lever to the
neutral position, the transmission stays in forward. Pull the control
lever to the reverse position, the transmission goes into neutral.
You cannot get to reverse. With the motor not running, the
transmission shifts fine. Any suggestions?

"Billgran" wrote in message
om...

wrote in message
om...
I dropped the lower unit on a 1989 Yamaha V6 to replace the water
pump. While removed I had the mech replace seals and bearings. He
had to apply heat to the lower unit to disassemble (corrosion).
Setting on the bench the transmission shifts fine from forward to
neutral to reverse. Once installed, with the motor running, it is
difficult to shift into forward. Pull the control lever to the
neutral position, the transmission stays in forward. Pull the control
lever to the reverse position, the transmission goes into neutral.
You cannot get to reverse.

Prior to 1993 Yamaha used regular steel, not stainless steel, for the
shift
rods that ran from linkage under the carburetors down to the gearcase.
Mercury had the same system years and years ago, and Yamaha "copied" the
Merc gearcase design. These rusted away over time and as the diameter got
thinner as the rust flaked off, it turned into a "torsion bar" and would
not
shift out of gear while under load. They would twist but not turn the
gearcase shift shaft.

If you look at the rod at the opening near the lower mounts, you may see
where the diameter has corroded away from about 1/4 " to around 1/8". The
bad part is that you have to remove the powerhead to replace the shaft. On
an engine that old in sal****er, it may be almost impossible to remove the
long mounting bolts holding the powerhead onto the midsection.

This is assuming that you reinstalled the shift rod splines correctly and
there is no internal problems with the gearcase.

Bill Grannis
service manager

Maybe you just need to adjust the linkage. My Mariner 15 (Yamaha) has an
adjustment nut in the middle of the leg. Also where you split the linkage
when dropping the leg.
Bill