Mecury 9.8 110 - Shifts into gear automatically

[rstier]

Hi, I just picked up a 1974 Mercury 110 9.8 for my son. It's what I grew up on, so I'm willing to feel some pain of having an old motor for nostalgia purposes. It runs fine, but when you are in neutral, you can hear the RPMs change and it will switch into gear on its own for a few seconds and then back to Neutral. I know the guy just replaced the impeller, so maybe something didn't go back right. Any thoughts on what I should be looking at would be much appreciated.
Thanks,
Ron

 

[rstier]

Any ideas on this one? Thanks.

 

[7920hpMercury]

IMHO, few thoughts for you:
1. these are great little motors, good find!
2. I would install a kill switch since these did not have one (good to have and use, ask me how I know!). Wire up the aftermarket kill switch to ground the orange wire off the switch box.
3. As for going into forward, I would check the spring that detents into the shift mechanism under the carb. I would spray the whole shifter mechanism with WD40 and relube (unless you want to pull the power head, and remove and clean everything). I am assuming the lower unit shift shaft is mated up correctly so it will shift Fwd/Neutral/Reverse ok. If so, I would guess you just have some slop in the shift mechanism/linkage under the carb and so just need to clean that up and adjust the spring tension some. You might could bend the spring down some or better yet install a new spring. This spring is also slotted a little to allow some adjustment, so you might could play with the spring location some to get a firmer shift point.

Hope this might help.

 

[rstier]

Thanks, I agree it is a good little motor! I just had to clean the carb initially and the only remaining issue is it kicking into gear from Neutral every now and then. I'll take a look under the carb when I am up at the lake again this weekend and see if there is something going on there with the spring. As far as the stop switch goes, there is one installed from the factory, so I should be good. It is located right in front of the forward gear lever (black button) on the left hand side of the bottom cowl.

Thanks again for your help!

IMHO, few thoughts for you:
1. these are great little motors, good find!
2. I would install a kill switch since these did not have one (good to have and use, ask me how I know!). Wire up the aftermarket kill switch to ground the orange wire off the switch box.
3. As for going into forward, I would check the spring that detents into the shift mechanism under the carb. I would spray the whole shifter mechanism with WD40 and relube (unless you want to pull the power head, and remove and clean everything). I am assuming the lower unit shift shaft is mated up correctly so it will shift Fwd/Neutral/Reverse ok. If so, I would guess you just have some slop in the shift mechanism/linkage under the carb and so just need to clean that up and adjust the spring tension some. You might could bend the spring down some or better yet install a new spring. This spring is also slotted a little to allow some adjustment, so you might could play with the spring location some to get a firmer shift point.

Hope this might help.