Outboard doesn't fall into reverse

[tat]

I have a yamaha 9.9 (F9.9BE), approx 1980s.

The prop touched a shallow and came off its spindle and was lost. A new prop was fitted. All seemed well. The boat went forward, but then it was discovered that it wouldn't engage reverse.

I took the engine out to see more clearly. The forward easily drops in, and out into neutral, but it will not fall in to reverse; I can feel a slight resistance at the point where it should fall in. However, if whilst it is in neutal I turn the prop just a little, then it will easily fall into reverse as it should.

I have a manual, but it would be beyond me to take it all apart.

I am thinking that some damage has been caused somewhere. But then perhaps it could just be something and nothing, just some adjustment. So this is why I am posting. Please could anyone be able to suggest what might be going on, and the remedy.

Plan B is to fit another gearbox.

Any ideas?

[Franziska]

Check if adjusting the link screw between lower and upper leg helps.

If not, I'd take the lower leg off, it's not too complicated to do this. Than move the push rod of that lower leg while turning the prop to see if you can achieve forward neutral reverse.
If that's working fine, the gear box, which is probably be the most expensive part to fix, is almost for sure OK.

Than try if the upper gear shift rod gets properly moved when operating the gear shift lever.

We have two 9.9 which are fairly new, but adjusting them is a pain.

When trying all this, do it directly on the motor and not via control cables.

[tat]

Thanks Franzisca. I have taken one off before and done exactly that, so i will whip it off to check that, but I think it is in the gearbox, a synchromesh problem or something.

[Sardean]

Originally Posted by tat

Thanks Franzisca. I have taken one off before and done exactly that, so i will whip it off to check that, but I think it is in the gearbox, a synchromesh problem or something.

When motor is off it is normal to have to spin prop to engage reverse. The selector in gearbox is pushed to reverse position by a wedge on end of the push rod and when you engage fwd the push rod is lifted up out of way and a spring inside gearbox pushes the selector into fwd.
So you will not feel any pressure when selecting fwd but will alway feel a bit when selecting rev and it wont engage rev or fwd unless the gears line up. That is why if motor is off sometimes you spin prop a little to select rev, in fwd the gearstick will move easily then if you spin prop a little you will hear the spring push the selector into gear, unless gears were already alligned.

[tat]

Originally Posted by Sardean

When motor is off it is normal to have to spin prop to engage reverse. The selector in gearbox is pushed to reverse position by a wedge on end of the push rod and when you engage fwd the push rod is lifted up out of way and a spring inside gearbox pushes the selector into fwd.
So you will not feel any pressure when selecting fwd but will alway feel a bit when selecting rev and it wont engage rev or fwd unless the gears line up. That is why if motor is off sometimes you spin prop a little to select rev, in fwd the gearstick will move easily then if you spin prop a little you will hear the spring push the selector into gear, unless gears were already alligned.

Ok, I think I grasp that, thanks. But what when the motor is running?

The truth is that the engine is my mate's, and I am helping him, so I wasn't present when he couldn't get it into reverse, which was when his engine was running.

I have the exact same engine and remote as his. I have never had a problem with selecting reverse when the engine is running, and i can't think of a time when not running

I wish i had had a try selecting reverse on his engine when the engine was running, but I think that it simply just wouldn't go into reverse because it either will or won't engage. I had no reason to doubt what he reported.

I suppose that I could put it back in the water and give it a go with the motor running, just to eliminate that possibility.

Thanks for explaining the mechanism.

I might put it in the water and try it, then if not I will remove the gearbox and try with the lower end of the pushrod. If it still isn't working then I could take it to an outboard mechanic, and failing that then look for a replacement gearbox.

[Sardean]

Originally Posted by tat

Ok, I think I grasp that, thanks. But what when the motor is running?

The truth is that the engine is my mate's, and I am helping him, so I wasn't present when he couldn't get it into reverse, which was when his engine was running.

I have the exact same engine and remote as his. I have never had a problem with selecting reverse when the engine is running, and i can't think of a time when not running

I wish i had had a try selecting reverse on his engine when the engine was running, but I think that it simply just wouldn't go into reverse because it either will or won't engage. I had no reason to doubt what he reported.

I suppose that I could put it back in the water and give it a go with the motor running, just to eliminate that possibility.

Thanks for explaining the mechanism.

I might put it in the water and try it, then if not I will remove the gearbox and try with the lower end of the pushrod. If it still isn't working then I could take it to an outboard mechanic, and failing that then look for a replacement gearbox.

If it goes into gear with motor off and slight turn of prop it should work with motor running, at idle as this is only time to change gear. If it make a grating sound when in rev gear then shaft is not being pushed down enough and may require adjustment.

If you can select gears with motor off then it should be ok., but if you cant with motor running then there may be some internal damage to gears. But you would normally hear a horibble rattle from gearbox if there is internal damage. Drop the oil and check for metal in oil if your worried. Get back to the forum with more details and im sure someone will know the problem

[Sardean]

Fyi in the first photo i am pointing at the selector, you can see the reverse cog the selector slides back and three squarish teeth slide into the middle of reverse cog when you push down on gear stick. The second photo shows the forward gear cog that when you move stick to forward a spring pushes the selector back against that cog

[alansmith]

No need to get boat in water. Just hook up hose and ear muffs. Be very careful around that prop. In fact, I would take it off just for safety when you try it out.

I just finished a carb rebuild and water pump rebuild. Now I have an oil leak in the gear box. So it looks like I get to learn how to pull oil seals and reinstall on upper and lower gear case. I’m learning a lot of new skills on this little 4 hp 2 stroke Johnson.

[Sardean]

Originally Posted by alansmith

No need to get boat in water. Just hook up hose and ear muffs. Be very careful around that prop. In fact, I would take it off just for safety when you try it out.

I just finished a carb rebuild and water pump rebuild. Now I have an oil leak in the gear box. So it looks like I get to learn how to pull oil seals and reinstall on upper and lower gear case. I’m learning a lot of new skills on this little 4 hp 2 stroke Johnson.

You could be superduper saftey conscious and take prop off, but i don't know anyone who takes the prop off when flushing or starting motor out of water and putting it in gear, i have a mate who's poor dog attacked the spinning prop, dogs ok but mates wallet is a lot lighter

[tat]

Thankyou all for your advice. I thought about it all and suggested to my pal that he takes it to an outboard mechanic, and it needs a service at the same time. It's for the best, and they will be able to test everything is working properly.