1985 15 hp acting like its going into gear in neutral

[Shadrak Designs]

I have a 1985 15hp mariner that I just changed impellor in now it keeps acting like it want to engage in neutral it just keeps making a thunk sound.... Does anyone know if I just need to adjust the shift linkage to fix this.......

 

[Texasmark]

Backing the truck up, how did things do before you dropped the LU? Where were the shifter lever and LU shift position when you pulled the LU? Where they when you put it back together? What did you change that could effect the shifting mechanism? There is a 3 position shifter cam and a splined interface that is pretty bullet proof if you pay attention to what you are doing. Answer the questions and we'll know what to tell you next!

 

[minuteman62-64]

Did you uncouple the shift shaft at the mid-point when dropping the LU? If so, you may have reconnected it in a different position. Also, may not have had gear case and shift lever in sync when re-coupling.

Other than that, see above post

 

[Shadrak Designs]

I removed pin from top up next to motor but I believe I did spin it once on the thread that connect the 2 shafts together but I made sure linkage was depress fully into gearbox and made sure lever was in down position which would be reverse I believe....

 

[minuteman62-64]

I have an '82 30 HP with (pretty sure) the same shift shaft configuration. On mine, one turn off on the coupling nut doesn't cause a shifting error. What does happen in mine is that it will pop out of reverse when I'm fiddling around with it. If that happened, and you didn't notice, it might be the cause of the problem.

How about try this: un-do the mid-shaft coupling nut, make sure gear box and shifter lever are in sync, and, re-couple shift shaft making sure it doesn't pop out of gear? If necessary you can manipulate the lower shift shaft with pliers through the access port.