50hp Evinrude barely turns over, control box wiring

[ba_50]

Hi,I've got what I believe is a 1972 50hp Evinrude with manual Power pilot shift box. The plate and number are missing but I have an almost identical motor with electric lower unit and it is a 1972.It recently had a different piston put in and just barely turns over. The starter and battery are ok. What could this be? I put oil in it in case of a dry cylinder.I also need a wiring diagram for the Power pilot control box. There are two white wires coming from the switch at the back of the box that need to be hooked up. There is also about a 4" black ground wire that goes from the first hole back of the igintion switch to ?. My manuals picture isn't good enough to tell. I am transferring an ignition switch from an electric shift to the manual shift.Thanks for any information you may send. Bob

[DanielMiller123]

I also have a 1972 50 hp evinrude that I would like to switch over to manual from the pushbutton control. This is my first boat and judging by what I have read I really chose a Dandy!! Any help would be greatly appreciated. Model # 50273

[reeldutch]

on wat size boat are you using it and what size prop

[DanielMiller123]

I have a 14 ft 6 inch bomber by fiberking. I honestly dont know how to tell what size prop. I am new to this. How do you tell what size the prop is? Also the model number is a 50273c and the serial number is E07742.

[reeldutch]

Does it turn over without the plugs in?a new piston might give you 165 psi check the compresion to make sure if the starter doesnt work you can use a pull cord to do the compression test.i think your fine your old starter might be tired.reeldutch

[Walker]

Jump the starter directly from the battery. If it still doesn't crank fast you have either a bad battery or a bad starter.

[ba_50]

Thankyou all for your interest. I tried to jump start it off a new battery and tried the starter off the spare motor and neither helped. I doubt if two starters could be bad. I'll try a compression test and pull cord and see what I come up with. Daniel, I don't know much about electrical boxes and these motors, but your lower unit might need changing as it might be wired to the box somehow.Thanks. Bob

[reeldutch]

did you try a brand new starter? and it didnt turn over???check also your starter solenoid.does it turn over with the plugs out?reeldutch

[Droll]

Can you turn the flywheel by hand ? if so , how are the battery connections .Clean ALL electric connections between the battery and the starer ,6 GA cabel (red + black ).If not , when replacing the piston ,you did check the ring end gap ?? ( max 0.017" , min 0.007" )

[ba_50]

No, I didn't try a new starter or clean the connections. Yes I turned the flywheel with the plugs in and out. Even when they are out it turns hard. It will turn evenly with the starter this way. Too hard for a rope pull( plugs in). Both cylinder pressures were 40-45# which is 10# less then my 8hp Johnson.I guess I'll try cleaning the connections, but I don't think it should turn that hard with the plugs out. Really strange. Thanks. Bob