93 Force 50hp Gears/Shifting/Vibration issues after changing Impeller and gear lube.

[tuggeyt]

Hello let me first apologize for this being so long but I know as much knowledge as possible helps troubleshoot so let me just say thank you for your patience.
As you can see I am new to this website but I have been on here a lot reading previous posts and have got a lot of knowledge and information from here.
However I have run into a problem which is out of my hand and I don't want to take a chance of messing up something or messing something up more than I have. So I decided to reach out on here in hopes of getting some good instructions/troubleshooting help. Ok to start off I recently got a older 15' Cobia Bowrider boat with a 1993 50hp Mercury Force. I got a great deal on it. I traded some stuff valuing around $600 for the whole setup.

The motor was not running and previously sat for about 5-8 months. To get the motor to run all I needed was to change the battery(Lucky I know) lol..... and the motor ran good in forward/ reverse/ neutral... But the boat has been used in salt water and sat for awhile so I figured it needed some basic maintenance done to it to insure quality and long lasting function. Main focus being the impeller and gear lube. I will use the diagram provided by Boats. Net for parts replacement ( link at bottom) to explain some parts and things I touched/moved. Anyways, I bought a new Impeller, gear lube and begin the procedure to replace them.

Now let me just say I came into this a beginner/novice in the boat world but just did a lot of research to help me complete and I felt relatively comfortable with the job until now :facepalm: lol. I started by removing the nut that holds together the gear shift linkage. Then I removed the bolts holding the lower unit up to the midsection and gently removed the lower unit from the motor. Now to remove the waterpump housing and impeller I removed the Driveshaft assembly pole(#55 in link) from the gear unit by pulling up(took it out of the gear unit) then replaced and cleaned up everything nice and impeller didn't even need replaced but went ahead and switched it.
While that was out I figured I could go ahead and swap the gear lube. I drained it all out nice and put new lube in to it through the hole the driveshaft pole was in
with the vent screw out and made sure I followed spec for amount to use and everything went good. Now during this process the gear shift rod got knocked back and forth a little unscrewing it. If you look at the diagram look at #44 and #50 I think these connect. If so I believe it was the #50 pole that came unscrewed. Now I just made sure it looked right and screwed it all the way back down. Pushing up and down on it seems to be fine(as if it was shifting from forward to reverse).

Now got everything back together regarding the waterpump/impeller/driveshaft rod and stuff(so I think) and got it ready to connect back to motor. Now one thing I did not know and read before it was to late is to put it in forward before removing the lower unit. Anyways, took me like 5-10 minutes to realign/ajust and get the lower unit to connect to the motor again. Screwed all the bolts into place and reconnected the gear shift linkage(which was a pain). Now everything was back together and seems to be good to go. I started the motor and everything seemed fine. In neutral motor sounds great. I put it in forward and boom sounded like crap.

It shifted into forward but sounds horrible like a mix between a rod knocking and metal clunking and it seems to vibrate harder than it should. I turned it off checked around everything and started it again I put it in reverse and seems to be fine and sounds fine. Put it back in to neutral then into forward and this time it didn't go into gear. It stayed in neutral. So I pushed the throttle up more and about 3/4 the way up it kicked into forward but still sounded like crap. I put it in neutral and shut it off I jumped off and went to spin the prop in neutral and it spins fine like it should no resistance. I then put it into forward and tried the same thing and it still spun with no resistance as if it was still in neutral so then pushed the throttle all the way up and then tried to turn the prop and it felt like it should in gear and was tough(er) to spin.

So then I decided I needed to get some outside help before I end up turning this into a parts motor lol. I think I just messed up the gear linkage or maybe miss aligned it or something but how do I go about correcting it? As much help/info is appreciated.

Thanks for reading all of this and please be patient with me as I still am a novice/beginner in the boating world and don't know many parts/ names/ terms of boat motors and lower units. So when you respond please try to explain what stuff is the best you can. And if possible use part# in the diagram from the link I include.

Heres Link to Diagram http://www.boats. net/parts/search/Merc/Force/1993/H050412NF/GEAR%20HOUSING/parts.html
Take out the space obviously lol.
Thank you all for your help.

 

[Jiggz]

When you decided to screw the shift linkage all the way, you obviously misaligned the cable linkage as a result. Basically, what you need to do is to mechanically zero the shift linkage and the control cable. You are correct to screw in the bottom shift linkage all the way in with the shift coupler (in the gear housing) but now you need to zero the upper linkage with the coupling nut. Try using this first to zero everything before going with the control cables. After you zero'ed the linkage and everything works perfectly, permanently mark the coupling nuts for future reference.

 

[tuggeyt]

By "mechanically zero" do you mean centered perfect between the two? When I reattached the linkage I thought I did it good. Is there something I can do to help me do this? Should I put the throttle in reverse or forward or keep it in neutral? Do I need to have a second person help me? Or is it pretty much a trial and error till it's right?

 

[foodfisher]

In forward, be sure of positive engagement, mark the shift rod at the housing level. In reverse, do the same. Adjust neutral to midway between the marks. Help not necessary. I believe after bottoming out on screwing the shift rod into the coupler, it's best to back off a turn or two? Edit: I didn't read your lengthy narrative, just feeding off Jiggs reply.

 

[tuggeyt]

Thanks for the response guys. Much appreciated. And sorry its so long but wanted to get everything out there lol.
Something I forgot to mention :facepalm: was that the clunking noise sounds like its coming from the driveshaft assembly pole if I was to guess.
Would the linkage still cause this? And the heavy vibrating?
Im going to work on this tomorrow. Maybe burn it down by the end of the day if I don't get it right lol.
Thanks again guys.

 

[Jiggz]

The grinding or in your terms "cluncking" noise is the clutch dogs grinding against each other because they were not pushed far enough to fully engage. Follow Foodfisher's instruction and after you find the mechanical zero you can "bias" a little bit on the forward shift. And I am talking maybe no more than 1/8 ~1/4" bias to ensure the forward clutch dogs never slip. During normal operation, never ease in the control lever when getting in gear; instead be snappy about it to prevent the grinding of the clutch dogs thus prevents unnecessary wear.

 

[tuggeyt]

Well I got to play with it today for about 4 hours and almost have it right. I can get it either to run perfect in forward or run perfect in reverse lol... Its a pain trying to get this right. I going to get back at it either tomorrow or Sunday. But in the mean time I have a new question. I had to unbolt the lower unit cause the linkage nut was being a pain and kind of got stuck... anyways when I took the lower unit down I seen there is this nasty black/tar like substance all around the waterpump housing area. The water that shoots out from the impeller is nice and clean. And the lower unit gear oil still looks good. what is this substance that built up? If people read this and didn't read my lengthy first post I dropped the lower unit few weeks ago and cleaned everything so it's not from long time build up. Also another thing is this motor smokes a lot... I know the Force motors are known to be smokers but how much is to much? Thanks again for all the help.

 

[Jiggz]

I would surmise the tar like oil is from the unburned fuel from the lower cylinder. If you have been running the motor in idle for awhile this will happen. As for smokes, it is heavy and expected when idling. Smoke is less when actually running the motor or when using synthetic oil.

 

[foodfisher]

Also, a lot of smoke can be expected if the fuel recirculating system is plugged up with gunk. Too much for me was " Geez, this can't be right!". Cleaning the system cleared it up.

 

[tuggeyt]

Ok when I finally get everything running good on it and can take it on a lake or something I plan to use some seafoam and clean it out. However I played with the shift linkage again today for about another 2-3 hours and still can not get it to work. It either works perfect in forward or reverse or it will be sloppy in one and perfect in the other. But no matter what I cant get it to work for both.

Closest I got was it was it worked in forward but in reverse I would have to have the throttle about 50% down before it kicked in to reverse. I would adjust it just a little and then it will clunk/grind in forward. It is really turning in to a pain lol.... Do you think maybe its because I screwed the linkage rod all the way? Well its not all the way its about 1/4 - 1/2 turn off cause if its not it wont go threw the hole that connects it to the upper part. Should take the lower unit off again and unscew the shift linkage a few times? Would that cause it to be off and work well for one and not the other or am I still just not getting the other part right? :facepalm:

 

[tuggeyt]

Wellll turns out that I did need to unscrew the linkage rod a few turns. After I did this and put it back to together took about 30 minutes of readjustments and now it works fine. Shift into forward and reverse nice and strong.... So thank you Jiggz and Foodfisher for the help.... However new quick question. After all the grinding/clunking of it not going in to gear. Would this cause some metal shavings in the gear oil? I drained a tiny bit out and there was some metal shaving in it. I just changed the gear oil prior to the shift linkage problem. It shifts good and feels like it goes into gear nice and strong. Should I just change gear oil again to clear it out?

 

[Jiggz]

It doesn't hurt to change the gear oil especially it only takes less than a quart to do so. And yes, those grindings do really eat out the metal on those clutch dogs and can prematurely wear them out. Change the gear oil even for just having a peace of mind. Lol