electric/pull start 25 hp mariner 2 stroke

Hello i posted this same thread in the mercurey/mariner section but i need help asap because i really want this boat in the water by friday...
I recently bought a boat with a mariner 25 hp 2 stroke im uncertain of the year but its probably from the late 80s or early 90s. It has a pull start as well as an electric starter. When i got the boat most of the wires from the motor to the ignition were coroded and nicked all over.Being avionics replacing all the wires and terminals from the motor to the ignition was no problem. I even did a one for one swap with all the wirering so as not to cross or mix up the wires. Yesterday i hooked up the battery and plugged the hose into the bunny ears and tried to start it. The only response from the motor i got was smoke billowing from one wire on the engine that runs to the ignition. It literally melted most of the sheilding off down most of the length of the wire. I checked my batteery and its putting out 12.3 volts so i dont thing its putting out too much power. Any help or guidance would be very much appreciated! I also noticed that the the starter was dropped down below the wheel dare i call it a fly wheel?

The only thing I can offer is that you are grounded somewhere where you ought not to be grounded. That is you have a dead short somewhere around that melted wire. Trace it and re-check all of your work.

Yeah i was under that assumption but being that i have no clue what wires signal what or ground what i have nothing to go off. Ive spent quite a few hours searching for a diagram or a schematic with no results. I cant even find a service manual because all the ones ive found are all for much newer models of mariner, but thank you im going to try to look it all over maybe ive missed something obvious.

THere was a lot in common with the Mercurys and Mariners in the under 100 HP range. I believe many of the parts were totally interchangeable. I'd search around for a Mercury manual. Also, up this way there are a few old marine engine mechanics around that probably know that engine well, so I would simply ask around the marinas and boat yards. I highly suspect that there is someone up and down the New River that knows that engine and may have a shop manual stuffed back in a corner.

yeah your right i was just looking for the quick fix so that i could have the boat on the water catfishing tomorro night but ive come to the realization thats not going to happen so i pulled the starter and i believe solenoid pn 89986054. behind them i found a small switch with a sheared off black wire as well as a sheared off yellow wire with a red line. most likely the black is ground but ive seen that yellow with the red stripe all over. so im absolutely lost now im going to need a manual or an expert, i can wire and troubleshoot an mv-22 osprey all day and night but this little 2 cyl 2 stroke has me stumped = (.....Its got me thinking cant i just bypass the electric start all togethor and just make it a manual start again? i mean its not going to effect the steering or driveablillity so why not?

On all the OMC brands, the yellow with red stripe wire is for the starter solenoid, which closes the solenoid to allow main battery power to go to the starter motor. It is probably the same color code for mercury/mariner. If that wire was grounded, or the solenoid has failed and stuck closed, then turning on the starter will heat it up. If that switch you discovered is actually the solenoid, then that is likely your problem. It should have three or four wires - the yellow w/red stripe you described, a black ground wire, and a heavy red wire usually directly from the battery. There may also be a heavy black wire for grounding the starter, or the the starter may simply be grounded through the bolts to the engine frame.

Now for my disclaimer - I'm not a marine mechanic by any means. I've just been around boats and motors for a long time and try to do my own maintenane and repair when I can. Currently run a Honda 225 on a 25 ft C-Hawk in the Chesapeake and offshore out of Hatteras.

Ok so last night i troubleshot the the solenoid with the battery disconnected i got an open between the 2 large terminals however with it connected i got continuity so i know thats good. that switch with the broken wires i found is the nuetral start switch...where the hell would those wires go to? and that yellow with red wire goes everywhere on the right side of the motor including to that nuetral switch.. Thanks for all the help so far!

Wayne,

I would post the essence of this thread on the Mercury Outboard forum on this site. At this point, I'm no help.