Minimal ignition wiring..

[not yet known]

Hello.. New here.. Name is Josh.. Putting together a mild sand drag, hill climb bike.. Bike in question is an 82 400 maxim.. For.. the life of me I can not figure out my wiring.. Im looking only to have hot to coils will a kill switch... Thats really all I want as I'll start the bike off a roller.. It would appear I need to hot the ignitor box.. All the wiring diagrams look just a bit different from each other.. And Im no electrical genius.. Wondering if anyone has or knows this model enough to recommend a down and dirty, quick hook up.. Also looking to remove charging components and trim down engine casings. Thanks for any help..

 

[not yet known]

Forgot to mention want to run total loss off battery to coils..

 

[BBS360]

Most diagrams floating around are for the various single overhead cam models.
I believe there is only one stock diagram for the double overhead cam Maxim's which can be found in chapter 6 of the manual here: http://www.xs400.com/threads/yamaha-xs400-manuals.4503/#post-46729

You pretty much only want components 6, 8, 9, the battery, a fuse, and a kill switch.
Run from the battery to the fuse, fuse to kill switch, kill switch to the R/W wire shown powering those components, and all the wiring/grounds directly connected to those components.

You may want to invest in a lithium battery. They will be lighter than stock for the same, or higher, capacity.
Plus they can recharge very quickly which maybe an advantage in between climbs.

 

[BBS360]

Interested to see how this goes.

I'm not too familiar with the Maxims but any covers you remove may need holes into the crankcase to be plugged.
On SOHC bikes there's a port between crankcase and stator that would leak oil unless plugged.
There's also a breather from crankcase into the starter cavity.
May be similar on yours.

The stator assembly is pretty different from SOHC models but I believe you may be able to entirely remove the steel shaft the rotor attaches to. That'd save you a couple pounds of weight in addition to losing the alternator but it would be another hole to plug.
Might be a challenge removing the chain though, as I believe it's inside the crankcase.

I'd keep the sprocket cover but you could remove a lot of material for weight/looks.

 

[BBS360]

DynaGlide split the crankcase on his DOHC bike: http://www.xs400.com/threads/xs400j-maxim-82-83-dohc-engine-rebuild.15715/

The photos might give you an idea of what can be removed without splitting the crankcase.

 

[not yet known]

Thank you for the reply.. Been working late and had no time to look at the wiring.. Im trying not to molest the original wiring as of yet.. that way I at least have something to go by.. The ignitor box has 2 plugs.. 2 grays, 2 orange, 2 black, black with yellow stripe, and that red with white stripe.. This is what im told as im color blind.. Lol.. So wiring is my downfall.. And when its lumped together its a mess for me.. From some of the diagrams it shows (and reflects on wiring) the red/white stripe as hot to ignition relay.. I believe thats where kill switch would go.. The orange is usually a yammy color for coil.. Ground is black. Grey?.. Thats where it gets fuzzy.. This of course all could be wrong in my head.. lol.. Im also wondering where its grabbing pickup? or more specifically how.. not wanting to tear it all apart at once as it still runs as is.. Just wanting to ditch all this bulk wiring and run a system im used to.. Thanks for any help..

 

[BBS360]

The wiring diagram in the manual linked in my post shows the wires you're trying to figure out.
You're right, the R/W will be powered from your kill switch.

Orange and grey are the left/right ignition coil and left/right pickup coil wires.
Might have to use a multimeter on the stock harness to determine which orange/grey are for the pickup coils vs which are for the ignition coils.
Might also help differentiate the wire colours if some are hard to tell apart.

 

[not yet known]

Ok.. So I have the harness apart.. On the coil end i have the two plugs.. There are 3 red/white hot wires.. Im suppose i jump hot between the two plugs then one to killswitch and battery?.. I need hot to both coils but does it matter how its connected.?. And then i need to have hot (red/white) to ignitor box.. I guess what im saying is i just run all hots together to the battery.? thanks anyone for any input..