redkow97 Posted March 13, 2013 Report Share Posted March 13, 2013 An acquaintance of mine had an electrical fire in his '71 CB750.This was last summer, and the bike has been in his basement since then. I offered to take a look, but if it's as bad as he says, I'm thinking of suggesting that he just buy a 'new' wiring harness.Does anyone have experience with wiring a bike, or this bike in particular? The extent of my work on motorcycle electrical systems is limited to unplugging the fuel injection bits on a 600RR and pulling the throttle bodies to swap cables.if the fire damage is limited to one area (he said his battery "exploded"), could we just solder in new sections of wire, tape it up, and replace the bad part?If so, what gauge wire would be appropriate? Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted March 13, 2013 Report Share Posted March 13, 2013 There really isnt much wiring in those old bikes. If his battery exploded its likely that the voltage regulator was out of adjustment (yes, adjustment....its electro-mechanical). Most of the wiring is I think 16 Hague except for the starter circuit which should be around 8 and some other high-loaf components that are maybe 12. It would be a good idea to replace the old style glass fuses with some blade type ones and swap out the rectifier and voltage regulator for something less archaic in a combined unit. Its a 3 phase alternator so just about anything should work. Color coded diagrams can be found for free online. Quote Link to comment Share on other sites More sharing options...
bshultz0930 Posted March 16, 2013 Report Share Posted March 16, 2013 im going to be out that way tomorrow if you want me to stop by and look at it. Quote Link to comment Share on other sites More sharing options...
redkow97 Posted March 16, 2013 Author Report Share Posted March 16, 2013 Thanks for the info. That makes me feel better about offering to look at it. Like I said, this guy is more of an a quaintance than a friend, so I don't want to step on his toes by taking over his project, but he also mentioned he's never even ridden on the highway, so I'm assuming he isn't an experienced rider or mechanic and will appreciate the help. I may price out the parts mentioned above and give him a rough estimate of what kind of expenses he's looking at. Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted March 18, 2013 Report Share Posted March 18, 2013 So what happened? Quote Link to comment Share on other sites More sharing options...
redkow97 Posted March 18, 2013 Author Report Share Posted March 18, 2013 We blew off painting and bike work and got wasted for St. Pat's day instead. Quote Link to comment Share on other sites More sharing options...
jester3681 Posted March 18, 2013 Report Share Posted March 18, 2013 I'd check eBay - a CB750 wiring harness shouldn't be terrible - they have new and cafe style, if I remember correctly. I've torn down numerous old Hondas and the wiring is usually pretty brittle. Add the heat of a fire, and you won't be soldering into the best material. That said, there isn't a lot to them and a lot of times there are multiple junctions in the harness. You may be able to replace sections, junction to junction, with no soldering at all. Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted March 19, 2013 Report Share Posted March 19, 2013 New harness will require messing with the kabillion connectors in the headlight bucket....fun. Quote Link to comment Share on other sites More sharing options...
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