Need help with BIG TWIN 40

[peterathomewood]

I have an evinrude big twin 40 model number 40752E ser no B3185. I need help with age and wiring diagram - I have six wires -two are obvoiusly HT to starter/solenoid ; two are lt from/to solenoid and there are two more - cut out and trickle charge?

 

[Paul Moir]

Re: Need help with BIG TWIN 40

Model number 40752 is a 1967 engine.<br />The generator for this engine is a belt drivin one on the opposite side of the carburator. If it's not there, the outboard will not charge.<br />6 leads suggests there's no generator. In that case, one of the fat ones is ground, and the other (red) runs to the starter (+). As for the other 4:<br />White wire: Applying 12v will close the solenoid to crank the engine (S on keyswitch).<br />Red/White stripe: Applying 12v will close the choke (activate the choke solenoid, ~6.5 ohms to ground)<br />Two black wires: These are the magneto wires. Shorting them together kills spark and shuts off the engine. They should never be connected to the 12v system. (Each connects to each 'M' on keyswitch).<br />Hope this helps!

 

[peterathomewood]

Re: Need help with BIG TWIN 40

Thanks a lot for a speedy reply. I originally thought it would not charge but was told "they all do!" It hasn't got a generator! There is a deal of strange wiring, hence the call for a wiring diagram of sorts but the info you gave me gives me enough to get it going in a bin full of water in the back garden! Thanks<br />Peter

 

[peterathomewood]

Re: Need help with BIG TWIN 40

Paul<br /><br />I have just read your reply again - I don't have a red/white wire coming out of the engine casing. The two non-black wires connect from the hot side of the solenoid (directly connected to the fat 12v to crank the engine) the other is the feed back to the sloenoid coil. All this works fine, the engine cranks like a maniac but will not start. the only response I have is a few bacfires - changing the plug leads stops the backfire but does not fire up the engine. There is a fairly weak spark along with fuel running out of the air intake after a few seconds of cranking.