Need some help.....

[Nate McVey]

I have a 14 ft. boat with a console run 1988 25hp Mercury that has been solid. We were heading across at wide open throttle and (I assume) it slipped out of gear. RPM's revved and we were dead in the water.

I shut it down, pulled the cowl expecting to find a busted linkage or something to that affect, but there was nothing like that. The engine runs great, but will not go into gear (forward or reverse).

Luckily a very kind man came by and towed us back to the landing where we loaded up and headed home. When I got home I drained the lower unit figuring there would be water or metal shavings in there but it was spotless. I pulled the prop and checked the clutch dog and gears and they all appeared to be functioning normally.

Any idea what could cause this?

[CAMAN]

Check the prop hub. Sounds like you could have spun it.

[Nate McVey]

Sorry, but what would I be looking for?

[CAMAN]

Make sure everything is turned off and put the motor in forward gear. Go to the prop and spin it, it should spin freely in one direction with a clicking noise, but the other direction it should be nearly impossible to spin. If it spins then it is the hub, and depending on the prop design, will either need a new prop or just need to get a new prop hub pressed in. Bring it into your local boat mechanic and let them take care of it. Having a spare prop onboard is always a good idea because of things like this.

[Nate McVey]

Here's the thing......lots of play (in and out) with the prop. In gear, it turns freely in either direction, but if I put a little pressure on it and push it in I can't turn it one way and get clicking the other..........very confused.

[CAMAN]

Remove the prop and see if you can do the same with just the prop shaft. Also see if the hub or prop shaft are loose.

[CAMAN]

Oh, and incase you don't quite know what the prop hub is, it's the inside portion of the prop, where the splines are that the prop shaft goes through. It's got a rubber ring inside that holds everything together. It is made like this so if you hit something or the stress is too high on the prop, the hub will slip and not cause damage to the motor. They can and do go bad especially if it hasnt been changed since 1988.

[Nate McVey]

I can do the same without the prop on.....kind of got fed up with it tonight so I'm going to go at it with fresh eyes tomorrow.

[CAMAN]

Alright, it sounds like something broke loose in the lower unit. Probably best to bring it in since it requires a special tool to open it up.

[marine_man]

Sounds like a clutch dog may have failed.

I'd take it in.

marine_man

[Nate McVey]

Sounds like a clutch dog may have failed.

I'd take it in.

marine_man

She went in this morning after I figured out it wasn't a spun prop. The guy said "see how it's doing this? Well it shouldn't be." as he spun the prop freely. Should know what's going on early next week.

[walleyemaniac]

I have a '88 90hp Yamaha that did the same thing. Broke the shift fork in the lower unit (lucky it didn't catch the gears when it went down). Just a fluke thing that happened. I suppose the number of times that things been shifted in and out of gear over the years just finally took it's toll.

[Nate McVey]

Well, gotta say that CAMAN was correct, spun prop. New prop, few seals and some lube and she was out the door. Looking forward to getting it out this weekend and thanks for all the help!

[CAMAN]

Good to hear! Glad it was something simple.

[Nate McVey]

Well, took the boat out today and the same thing happened again.....motor revved and the prop wouldn't spin. Luckily we were much closer to the landing today and didn't need a tow, but now I don't know what the heck is going on! I'm going to bring it back to the shop tomorrow.........

[morepower02]

Time for a clutch dog and possibly forward and reverse gears depending on wear pattern.

[boatfixer]

Well, took the boat out today and the same thing happened again.....motor revved and the prop wouldn't spin. Luckily we were much closer to the landing today and didn't need a tow, but now I don't know what the heck is going on! I'm going to bring it back to the shop tomorrow.........

Did it work at all?

[Nate McVey]

Quote:

Did it work at all?

20 yards from the landing is when it happened........

[boatfixer]

Did the mechanic say what the lube looked like? Any shavings in there, burned smell? Do you hear any other noises? ( I am leading up to something, just trying to sort out a few things)

[Nate McVey]

Bruce, I drained the lower unit as soon as I got home (the first time) and there wasn't any metal in it (that I could tell). No noises either time it happened, just revved and wouldn't move. I just got back from dropping it at the shop. The shop manager said the "kid" that worked on it didn't hook it up to the dyno after it was put back together, just figured it was good because it felt right. He said they would stand by their work and get to it first thing in the morning.

[boatfixer]

I hope he meant run it in a test tank. Running on s dyno means no prop. I would expect to find shavings if there is major damage inside the case. I have seen in the past, drive shaft spines stripped. Were you able to see if the hub had spun again?ru

[morepower02]

Strange I have yet to see a engine of this low hp take out a prop hub. The second odd thing is that the dealer put it in gear, spun the prop and told you it was a bad hub. I have yet to see a spun hub that could be made to slip by hand. They have all required high load situations to slip. Somethings not adding up here. Also what seals did they replace? I am assuming just the gaskets on the drain and fill plug. Otherwise they were into the case.

[Nate McVey]

To be honest, I didn't think my original prop was spun, definitely no metal shavings in the gear lube.......He definitely said dyno, it's possible he misspoke or I miss heard, but that's what he said.

The other thing that has me cheesed of is that they didn't call to see if I wanted them to put on a new prop the first time (which I told him was B as in B and S as in S when I was there today), they just put it on and told me about it when I went to pick up the boat.

With my old prop off is there a way to check if it's spun? This sux, never had any trouble with this motor.......

[morepower02]

If the hub was spun with the prop installed put the engine in gear and see if you can turn the prop without turning the prop shaft. Even if the hub is bad you cannot normally spin it by hand in gear. You have to be at a full throttle high load condition to make it slip. Something else is going on. I would start at the linkage adjustment and go from there. If you want to bring it to Shakopee I would be happy to have my guys look at it.

[Nate McVey]

Quote:

If the hub was spun with the prop installed put the engine in gear and see if you can turn the prop without turning the prop shaft

The shaft turned when I did this pretty easily, but then they said it was spun and I took their advice, paid my bill and left.

All the linkages seem to be functioning properly, none of them seem to slip as far as I can tell.

As soon as I hear from them tomorrow, I'll figure our what I'm going to do.....