1978 mercury 80hp with Merc control

[Donnyb83]

I recently changed my throttle/shift cables on my 1978 mercury 800 80hp. The cable barrels were already lined up with the old setup,however when I took it out on the water full throttle was only about 7 mph. It didn't kick in gear until about half throttle. Also the reverse lock wouldn't lock. Could that be because the cables need to be adjusted. Also how do I adjust the cables if the barrel already lined up. Can anyone help me out please. Kind of need step by step instructions to get this thing right so I can actually take my boat out and go fishing lol. My first boat as alot of you probably know from my ongoing questions lol.

 

[GA_Boater]

Reverse lock only hooks up in neutral and reverse.

It's possible the cables are reversed. Is forward and reverse working in the water? Does the warmup lever increase the motor RPM's?

On the cable adjustment - Put the control on neutral, check that the prop spins in both directions easily. If not, disconnect the cable on the motor, again verify the prop spins both ways and adjust the barrel until the cable drops onto the shift linkage.

For the throttle cable, push the control handle all the way forward and check the carb butterflies are completely open. If no, adjust the throttle barrel until the carb is fully open at full throttle and the throttle linkage is against the idle stop in neutral. Make sure the warmup lever is all the way down when checking throttle operation.

 

[Donnyb83]

Hey ga boater. Yes forward and reverse work. When put in gear it don't catch until maybe half way down a little further. Maybe even 3/4 the way. Then at full speed she's slow. Reverse worked but not sure how fast since the lock wouldn't catch and motor kept trying to lift out of the water so just used it quick enough to get away from the dock. Idle lever does increase rpms also on the engine. I had my buddy at the throttle while I was looking at the engine while in the water and he had the idle lever up while throttling forward. Is that bad? Could he of broke that by any chance. I know it's a new question and I don't think it broke but I think I seen someone post that it will break if that happens. I was pretty perturbed but didn't say anything since he didn't know.

 

[GA_Boater]

Try it with the warmup lever all the way down. With the warmup lever lifted it creates a bind in the throttle handle. Mine does.

The reverse lock is engaged by a cam rotated by the shift shaft. Don't remember, but did you have the lower unit off to replace the impeller? Maybe the cam is mispositioned.

 

[Donnyb83]

No haven't changed the impeller. Guy said it was almost new when I bought it. I will check though if I can't figure this thing out lol

 

[GA_Boater]

I hate to say it, but sellers can't be trusted, even me if I was selling.

Hold off on the impeller for a bit until the throttle issue is fixed or figured out. No need to make things more complicated........yet. :smile:

 

[Donnyb83]

Thank you ga once again I got everything fixed. Steering no longer clicking. Greased the motor swivel and used a bunch of pb blaster and a heat gun got it to move alot easier. Still a little hard but figure just keep spraying it and working it and hopefully it'll free up more. If not I'll change that. Now there's a new problem. I'm going to put a new post up. My GFS dad didn't think the engine sounded exactly right. So he started taking wires off. The top cylinder when the wires off makes no difference. The other 3 shut off the engine. I bought new plugs and same deal. I have spark in all cylinders. 75 compression on the guage. Any ideas. Close to putting this boat back on Craigslist as I'm getting very frustrated.