79 Merc 70HP throttle/shifting issues

[DrWiffel]

I?m currently getting towards the end of a rebuild project and am at the point where I am connecting the throttle/shifting controls. Before I connected the controls I wanted to give it one more test before I bolted them in. I can shift the motor into forward, neutral, and reverse, but the throttle was having issues engaging. I can freely move the throttle cable with the neutral throttle lever with no issues. I made some adjustments to the shifting cable with the black knob (no idea on the proper name) that is at the motor end of the cable and was able to get movement to full throttle after that. The reverse at that point would still shift but I can?t seem to get any throttle from it.

I?m at a loss here, and can?t figure out what could be causing this issue. I did some searching here and wasn?t really able to find anyone else that had had the same issue. Which makes me thing that it might just be something easy that I might be missing (or so I hope).

The serial number for the motor is 5128781

Thank you in advance for any help that you might be able to bring me. If any picture or other information is needed please let me know.

Thanks,
DrWiffel

 

[s.hadley81]

Is this with the motor running?

 

[DrWiffel]

I haven't tried starting the motor yet. I was going to do that tomorrow (Hopefully) but ran in to this issue.

 

[DrWiffel]

I tried starting the motor today. I was able to get it to pop over for a short period of time, but wasn't able to get it to rev to a higher rpm. It was running at more of an idle rpm and then shut off. A minute or less was the longest that it would run before shutting down.

I'm going to run to the store tomorrow and pick up a new fuel line that runs from the tank as that could be part of the issue.

Another issue that came up during my test was that the water pump was not pumping water out the back. I'm thinking that this could be from sitting for almost 2 years during the rebuild and that it would break loose if I was able to get a higher RPM out of it? or should I also go a head and pull it apart and replace the water pump? This is a side issue though and I will post another thread if I need.

Before I started the project the motor ran just fine and was always reliable.

Thanks again for any help!

 

[merc850]

Replace the water pump impeller, they don't break loose - if they do they won't pump water. Don't shift into reverse without the motor running or hand turning the prop. Do you have the cables on correctly? it sounds like the throttle cable is on the shift lever.

 

[DrWiffel]

Thank you merc for the response. I'll do that right away. Seeing as I had shifted the motor to reverse with out running it, what damage might I have incurred?

Here is how I have the cables set up


The shifter cable is on the top and the throttle is on the bottom. I verified the throttle with before installing using the throttle lever to see which one was moving. I hope that's right.

Do you know if there is a location on here where I might be able to find where a schematic drawing for the water pump might be or where I might be able to find some general replacement information for the impeller?

Thanks again!

 

[DrWiffel]

I went out last night and picked up a new line for the tank and a water pump. I decided that I wanted to try and start the motor again before replacing the water pump to see if maybe it just wasn?t getting enough gas to get the water through the motor. The engine fired right up with no issues except 2 things. The motor was running at full throttle and water wasn?t pumping out. So I shut it down right away.

I watched about 5 videos on YouTube on how to do the water pump yesterday. On a side note. Anyone looking to replace a water pump, it?s really not all that hard and you don?t need a schematic of the motor, just watch a bunch of YouTube videos on how to change one and you shouldn?t have any issues. They all seem to look pretty much the same.

Pulled the boat in the garage, pulled the lower and got to work. Because it was my first time doing one I took some extra time (about 2 hours in total) to make sure that I wasn?t missing anything. Put it back together without too many problems. But do have one question. The lower seemed to be in gear. When I twisted the shaft, the propeller would move. Is this something that I should be concerned about? I had the motor/shift lever in neutral when I started the project. The picture in my last post illustrates the position of where I had it set to. Did I screw something up by shifting it when it wasn?t running? I haven?t tried shifting sense putting the lower back on, but now I?m a little worried about starting it back up.

Here?s the old impeller




Here?s the new one



Work setup



After getting that all wrapped up I took a look at what could be causing the high revs. I took a look at the carb and it looked closed, so I?m not sure what was causing the high revs. I adjusted the throttle cable, and it didn?t seem to do anything within the carb. So I pulled the cable off. And tried to operate the throttle manually from where the lever where the cable attaches while watching the carb, and it didn?t seem to move from the closed position. I checked the choke lever to see where that was sitting, and it was in the down position where it should be. Do you think there is something that is stuck in the carb, or something that may have gotten detached?

Here?s the Carbs





That black lever is the position of the choke

 

[DrWiffel]

I did some research and seem to be finding my self answering my own questions, which is a good thing because shame on me for not doing a better job looking around.

Found the answer to the lower unit and figure it must have switched into gear some how when I took it off.
http://forums.iboats.com/forum/engine-repair-and-maintenance/mercury-mariner-outboards/10076720-simple-method-of-shift-shaft-setup-for-mercury-outboards

I'll give this a try before I try and fire it up again.

Any suggestions on the high throttle?

I'm hoping that after I have that figured out I can start on making sure it goes forward and reverse.

Thanks again!

 

[DrWiffel]

Well... I guess we can consider this one closed! merc850 was correct. The levers were mixed up. I knew what cable did what, but got it wrong on the motor:facepalm:. Switched them up this evening and the gear was shifting like it should and the carb was opening and closing like it was supposed to. I didn't end up having to taking the lower apart like I thinking I would have to do which was a plus. I'm assuming that I took it apart in forward and put it back in at forward so there wasn't any issues. Lets just chuck this on to being lucky. Everything is running as it should! Just need to do the lake test.

 

[merc850]

Yes it's easy to mix those cables up, when in doubt move the shift control, with cables free, all the way FWD and see which one goes first - that's the shift one.
It's snowing here so I can't even get to my boat!

 

[DrWiffel]

Snowing! That stinks. I'm actually surprised with the weather we had this year I'm MN. It's been a pretty mild winter this year. I have to have the boat ready here for next weekend to go sturgeon fishing so I'm in a bit of a rush. But with time to still get it all done correctly.

I did actually test which one was which before putting them on the motor. Problem was, I got confused which controlled what on the motor. It was actually pretty dumb and felt a little stupid after realizing the mistake. We've all been there though right?

So the first picture I posted, the correct setup would have been the reverse of that.

Thanks again