1973 mercury 40hp 7pin to 8pin

[Ffmedic166]

Just acquired a boat 1960 Crestliner 17’ aluminum boat. Doing repairs and cleaning up motor and bought new control cables and started to crack into the control box and all the wires are frey and brittle damn near all the way to plug to motor. So I can’t find any 7 pin so I was told to get a 8pin one. I have engine harness that is 8 pin and wiring to run to front of boat.

Question I have is how to wire the new engine harness to my old motor and add key switch. Will this wiring work? I know some wires will be bare and deleted since they won’t connect to anything.

thanks for any help!

 

[The Force power]

I'm confused?? what wiring is being replaced? the engine wiring or control-wiring into the control-box?

 

[GA_Boater]

I'm confused?? what wiring is being replaced? the engine wiring or control-wiring into the control-box?

started to crack into the control box and all the wires are frey and brittle damn near all the way to plug to motor.

 

[GA_Boater]

Medic - What's the serial number of the motor. There is a break in SNs for your 1973 motor and 2 different harnesses were used. The boatside harness may or may not be different.

 

[Ffmedic166]

I got it wired up with a 2010’s 8 pin harness both engine and control wires. Now my issue is I can’t adjust new control cable for shifting, maxed out and won’t get it into reverse. Also I motor runs but not sure I have idle mix screw set right. Bottomed out two turns backed out was not enough had to back it out 1/2 turn more.

 

[GA_Boater]

Before you get carried away - Take the shift cable off at the motor and see if you can shift into F-N-R. Also since this is a new to you motor, you need to replace the impeller and that may fix the shifting issue. The shift shaft and shift get out of sync all the time when marrying the lower unit and midsection. But do try removing the cable and checking if you can shift first, then replace the impeller.

Most likely the carbs need rebuilt.

 

[Ffmedic166]

Before you get carried away - Take the shift cable off at the motor and see if you can shift into F-N-R. Also since this is a new to you motor, you need to replace the impeller and that may fix the shifting issue. The shift shaft and shift get out of sync all the time when marrying the lower unit and midsection. But do try removing the cable and checking if you can shift first, then replace the impeller.

Most likely the carbs need rebuilt.

Carbs were removed cleaned and nothing besides the mounting gasket had to be replaced. I ran the motor today with bunny ears and got it to idle great and when it did quit running I found if I pump primer bulb back up it fires right up and runs.

not a betting man but I think I need to get a new primer bulb though it gets hard after about a crap ton of squeezing. Lol. I tried to remove fuel pump but I can’t get access to bottom bolt no room for my fat hands and fuel line in way, even tried to move that but no avail it started to twist the line. .

there is a lever below backside of swivel plate that once I push on it frees up and I can manually shift it. The new cables is maxed out on adjustment but will not slide far enough back to engage reverse. MOD EDIT - Not a good idea for your security and also defeats the purpose of the forum.

Also the controls are a Mercontrol box that I am sure I connected up right. It’s basic and simple design. With this coronavirus I have all this free time so why not knock this crap out only issue can’t dunk into water for tinkering.

 

[GA_Boater]

Your fuel pump need rebuilding. With the motor starting after squeezing your good bulb, it's running out of gas because of a failed fuel pump. It takes a few extra squeezes of the bulb to fill the carb bowls.

I forget to say earlier - Shifting into reverse without the motor running is hard because the gear teeth aren't lined up. If it doesn't snick into gear using the control or manually the same as into forward, turn the prop a little to line up the teeth.

 

[Ffmedic166]

Your fuel pump need rebuilding. With the motor starting after squeezing your good bulb, it's running out of gas because of a failed fuel pump. It takes a few extra squeezes of the bulb to fill the carb bowls.

I forget to say earlier - Shifting into reverse without the motor running is hard because the gear teeth aren't lined up. If it doesn't snick into gear using the control or manually the same as into forward, turn the prop a little to line up the teeth.

If I disconnect the linkage and slide the slider back it will go into reverse. The adjustment has no more room for the arm to move back.

Also the MOD edit really was not needed. I’ve tried to load pictures and it won’t load them on here. MOD EDIT - Removed

 

[GA_Boater]

If you can move move the slider through all 3 positions, your cable needs adjusted properly.

And it did need an edit. Taking things offline means the forum is degraded and someone with the same issue can't call you for advice.

Post pictures after looking at Forum Help in my sig and reading the Photo Tutorial. I'll be editing your last post, too.

 

[Ffmedic166]

Never mind....the cable has no more adjustment then what I have done.