Force 90 outboard won't catch in reverse

R N

Cadet
Joined
Jun 15, 2012
Messages
7
Motor was running fine. Last time I launched it the water level was a lot lower than usual and as I was backing it off the trailer I hit something underwater. Sounded like a rock. Still had reverse for a few minutes but it was making a loud clinking sound like the gears were barely catching. Had no issues with forward. In fact, I still took it out and just made sure I didn't have to go in reverse. As I was trailering it I lost forward and had the same noise. It sat on the trailer for a while because I didn't have time to do anything with it and didn't feel like paying another several hundred dollars in repair (just had the flywheel replaced because the magnets came off). Finally get a chance to pull the lower unit and take a look at it. Before doing this I fired it up and put it in forward and reverse. I didn't hear the clinking sound it had made a few months ago and the prop was moving. I shut it off and with it in forward I could turn the prop clockwise but not counterclockwise. With it in neutral it turned both ways. With it in reverse it also turned both ways and made the clinking sound.

Before I go any further, I'm pretty sure it's not a spun hub. I just had that issue on another motor this is not acting the same way.

So finally got some time and got it almost completely broken down and all the gears look intact. When I turn the drive shaft by hand clockwise the prop shaft turns clockwise. When I hold the drive shaft still I can turn the prop shaft clockwise but not counterclockwise. So it appears forward is fine. When I turn the drive shaft counterclockwise the prop shaft turns counterclockwise. If I hold the prop shaft while turning the drive shaft counterclockwise it jumps the gears. I'm not sure if that's normal or not. This is all with the shim cam out of the lower unit. I pulled the shift shaft coupler and the shim cam came out and I noticed an edge is broken off. It doesn't look like it should affect the operation of it but I'm going to replace it anyway.

My questions:

1. Are the drive shaft and prop shaft doing what they should be doing when I turn them by hand?
2. Could the gears just jumped out of place to cause the original problems and now that I've taken them apart and reseated everything it's working fine?
3. What position do I want the shim cam in when I put it back together and for this position should I have it in F, N, or R?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,183
Re: Force 90 outboard won't catch in reverse

Year? Serial#?They made a lot of 90's
Since it's apart: close up pics of the clutch dog face and gear faces.
The clinking in gear.Sounds like the linkage needs adjusting.
Older models.Under the intake is a screw with a nut(1/2") possible it came loose??
Newer models:the shift linkage needs adjusting?

Shim cam??? Pics?
 

R N

Cadet
Joined
Jun 15, 2012
Messages
7
Re: Force 90 outboard won't catch in reverse

1996. Raining hard here so the serial # will have to wait.

Here are some pics. 2nd one is the shim cam.

force7.jpgforce1.jpgforce2.jpgforce3.jpgforce4.jpg
 

R N

Cadet
Joined
Jun 15, 2012
Messages
7
Re: Force 90 outboard won't catch in reverse

Anyone have any ideas. I'd like to get this thing put back together in the next day or 2 before I forget how it goes back together and end up with some left over parts! ;)
 

ENSIGN

Lieutenant Junior Grade
Joined
Jun 21, 2009
Messages
1,179
Re: Force 90 outboard won't catch in reverse

Looking at your pics the clutch and gear mating surfaces are rounded over and need to be replaced.It's just normal wear for a older motor and is mostly caused from shifting to slow.
 

R N

Cadet
Joined
Jun 15, 2012
Messages
7
Re: Force 90 outboard won't catch in reverse

Thanks. Would that cause my initial problem, though? Or did the linkage just need adjusting?
 
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