Hit a stump! 1995 Yamaha F9.9 MSHT

[rebelblue]

On my way back in last night, I was in an area of the lake I'm unfamiliar with and found myself too close to shore. Hit a submerged stump at nearly full throttle before I could veer into deeper water. Powerhead is seemingly fine, but the prop will not engage when put in gear. I took the motor off the boat today and laid it down. I removed the prop hoping it was a shear pin, but now I know this motor does not have one (splined shaft). I could spin the prop in forward and could feel/hear gears turning inside. However, I could not shift it into reverse-- the shift lever just refused to go backward.

At this point, I'm planning to take off the lower unit to see what's bent/broken/etc. A few questions:

1. Any guesses on what the problem might be and/or what I ought to be looking for?

2. Any words of caution or other "hey, watch out for X" specifically pertaining to the lower unit removal of this outboard?

3. While I have the thing disassembled, what maintenance should I get done in addition to (hopefully) fixing the original problem?

Thanks so much for taking the time to read my post and offer any suggestions.

Cheers.

 

[Bifflefan]

So I guess its ridiculous to ask why you were going "nearly full throttle, in the dark", at all, let alone in a place you don't know.

As to your questions, get a book before you start or let a pro look at it. While I don't know Yamaha, I can only guess there are things that need special tools to put it back together.

 

[rebelblue]

While letting a pro look at it would ensure I wouldn't have to worry about any of my questions, I don't see it providing much in the way of learning something about the motor. I may well need to take it to a pro and I certainly will if I can't fix it myself, but that's plan B.

A book would be nice indeed. Do you have any suggestions? I've found the parts list manual with exploded diagrams of everything as well as the owner's manual, which is not a very big help.

Ridiculous to ask why? I suppose not. Helpful to ask why? Not really, but thanks for the smack upside the head. Now I just might not do it again.

 

[racerone]

Any pictures ??----Any damage to the front of the gearcase ?-----Any damage to the prop ?------Have you checked gearcase oil ?

 

[rebelblue]

No damage to the gearcase and no damage to the prop. Gearcase oil is still in there and there aren't any leaks. Here's a pic that shows as much. I just built the motor stand during my son's nap time. I probably won't get to removing the lower unit for several days so I'm gathering as much info as I can in the mean time.

Thanks for the questions, @racerone!

 

[racerone]

If there is no damage then maybe you did not hit anything.----Maybe something broke in the gearcase and it locked up.----Makes you think you hit something.--------Drain the oil for a " look see "

 

[rebelblue]

I'll drain the oil and take a look for sure, but I know I hit something. The strike not only jarred me forward, but it also muscled through the manual tilt release lock/lever and the motor to tilted up out of the water and pointed the prop at the stars. I had to push it back down.

 

[rebelblue]

Got it apart and found a sheared drive shaft at the pinion gear. Thanks for the thread views and replies.

 

[rebelblue]

Also, here's a link for the F9.9 & T9.9 service manual just in case this can help someone else:

https://docs.google.com/file/d/0B6B...Zjc5LTkzN2YtZWJmOWRkNzk2ODJk/edit?hl=en&pli=1

 

[racerone]

I am not surprised by this result, not at all.

 

[rowboater]

Just curious how can you shear a driveshaft and have no damage to the prop ? Seems next to impossible a lower unit could flex that much.Unfortunately I have hit many things over the years that have bent props,sheared pins and spun hubs but never sheared a driveshaft.

 

[rebelblue]

I hear ya, @rowboater. Here's a shot of the prop. It's not the prettiest in the world, but it looks no worse after the hit than it did before it.

 

[rowboater]

Thats really something it even looks to have a rubber hub.Learn something new everyday.Thanks for posting the picks and good luck in repairing it.