Hey all. Had my '86 sitting for a couple of months since the last ride. I decided to take her out a few days ago for a spin, and it started fine, but would stall if I gave it a bit of throttle while still idling on the sidestand in neutral. OK, so i figured it just needed a little longer than normal warm up.

It's dusk out, and I also notice some wafting "steam" from the front of the bike.. I'm thinking that's odd.. she's been stored inside all this time, there shouldn't be any dampness... I finally catch a whiff... oh damn, that's electrical!!!

So.. tear down so far has turned up the outer wrapping around the main harness melted in several areas. However I have not yet found any damaged wires. The bike will still start... my meter shows power output settling at 14.23 volts.. a little higher than I'd expect per the service manual specs, and this is only at idle speeds. I haven't ran it for long, no need to melt my harness further!

Questions are:
- Think my regulator is done in? Or should I be looking harder for a short somewhere?
- Could the inability to give it any throttle be a sideeffect of the electrical issue? Or am I likely looking at a 2nd issue, with dirt in the carbs from sitting 2 months?

Thanks folks!
Richard

Check the voltage as you rev the engine - shouldn't go over 14.5 or so.

I would locate, using an ohm meter, and repair any melted wiring before turning any electrical circuit on, including the ignition. There is obviously an issue. In theory, everything should be protected by a fuse. Maybe some owner installed wiring possibly not done correctly. IIRC, the on;y wiring not protected by a fuse is back by the Jbox, the hot lead going into the Jbox, and the heavy wire leading directly to the starter from the solenoid.

Richard

Let me see... 14.23 volts are idle is a problem.  It should be around 12.  Have you checked you voltmeter lately?  Can it be out of cal?  I'd put it on your car battery (not running) and see... you should get around 12 volts.  If so, it's accurate, and you have a problem.  Yes, the regulator would be the most probable cause.  You can test it once you remove the alternator, the cover, and the regulator (I just had to last month).  Probably be able to find an alternator cheap on ebay... the aftermarket regulator is $80.  You mentioned "per service manual specs", so I'm figuring you have one, and you can find the check method there.  Before you head in and remove the alternator, there is a connector behind the starter solenoid.  Disconnect it and take a voltage reading with the bike running; I believe the procedure and specs are in the manual.

Steam wafting from the "Front" of the bike.  Are you sure it was electrical, and not coolant?  When they leak coolant they steam... if it's electrical, you'd think it'da taken a fuse, but as I say in the medical equipment repair field of 27 yrs, "a $450,000 x-ray unit protects a $0.29 fuse".  And if it is shorting... well, wondering if that is why the voltage output is up?  I mean, I doubt it, but I also wonder if a short is lowering the battery and the alternator is trying to make it up??

Carb wise, drain them into a clean container.  Tube on the nipple on the float bowl, good tool to loosen the drain screw on the bowl.  Odds are carb #3 will have crap in it, as it is the first after the feed fuel line.  Drain'm all though.  Then put it on prime for about 30 sec, not letting go of the petcock... then back to on.  Not letting go is a means of not walking away and forgetting to turn it from prime.

I'd rule out one thing at a time.  Yes, your actual problem might be affecting the other things.  Also, remove the air filter and look in the housing.  Want to rule out a rodent moved in.

Mark

Thanks everyone so far for your replies....
I'm owner #3.. but I bought it with 18000 km on the clock 10 yrs ago... it was totally unmolested by its prior owners, and so far, relatively unmolested by me ;-)  I have to admit to heavy riding in rain and everything else in those 10 years, but I've kept up on the maintenance.

I'm pretty confident in my meter... Plus it's backup meter says the same thing ;-)

"Steam" was just a descriptor for what I saw rising.. oh it was definitely SMOKE... just hard to tell the colour as the sun's going out..

I actually can't rev the engine to check max voltage output because of the secondary issue... gotta love the 2 at a time issues.. she was running fine when I came home from a 200km trip.. but 26yr old components.. well, guess they sometimes do fail!

Had to do some yard work, but now it's time to dig in a little further.. maybe I do have a mouse living in the airbox 

maybe I do have a mouse living in the airbox 

  Not uncommon...had a family of the critters in the main hitch tubing for my boat.  They decided some wire insulation would be a tasty snack and for a while I couldn't figure out wht I only had one trailer light...

Let me see... 14.23 volts are idle is a problem.  It should be around 12.  Have you checked you voltmeter lately?  Can it be out of cal?  I'd put it on your car battery (not running) and see... you should get around 12 volts.  If so, it's accurate, and you have a problem.  Yes, the regulator would be the most probable cause.

Me thinks you should be sure of your own meter and facts here..... A standing battery in good shape should read anywhere from 12.5 to 12.8 volts or perhaps higher all depending on state of charge; with any voltage less than 12.5 considered to be in need of a recharge. While installing the new battery in my Concours this morning I went about checking a total of 5 batteries and all read well above 12.5 volts with two known good meters. Same can be said for the 14.23 voltage at idle being a problem as my bike idles at 13.9 volts; while the Concours Service Manual does list 13.5 to 14 volts as a normal charging voltage this alt as used on numerous other bikes such as the ZXR list and are known to charge as high as 14.8 volts or even a little higher.