Sparks were flying and popping sounds too

[Red_Hen]

This is a weird post - met a friend for dinner tonight and parked my R65.  

Ignition was off.  Double checked to be sure side stand was all the way forward.  When I put my foot under the bike it sounded like someone was throwing down those little popper balls like we used to buy in Tijuana.  Sounded like a million little pops.  My friend says he saw sparks too.

After dinner, got on bike; she started right up and everything is cool.

Any ideas of what could have occurred?  I was eating at a restaurant on the lake but bike was not very close to the waters edge.

Hmmm?

[Bob_Roller]

Sounds like 'hot' wire, one that power to it all the time regardless of the key position, either is coming loose, or is chaffed through the insulation .

I would have a good look at the wiring coming from the positive lead of the battery .

[Red_Hen]

maybe the hot wire going to the horn relay - but it has a fuse in the line - how could that be?  maybe something else.

[Rob Valdez 79 R65]

You have a horn relay?  Do you have aftermarket horns?  Did you add the relay?

I would go with Bob's suggestion.  You need to remove the tank and have a GOOD look around.
Even beneath the starter cover.
Disconnect the battery negative wire before anything.

[Julio A.]

You said a friend saw sparks. Where exactly did he see the sparks?

[Red_Hen]

Think he saw sparks under the bike - is it possible my Sidi riding boots with a metal buckle acted as a conduit?

I installed a Fiaam horn a few months ago from O'Reilly Auto - I did run the positive wire, with  fuse along the top rail of the frame.

I'll have a look this weekend.  

[Rob Valdez 79 R65]

I installed a Fiaam horn a few months ago from O'Reilly Auto - I did run the positive wire, withfuse along the top rail of the frame.

First - did you install one each of the high and low tone horns?  That has a significant improvement over just one of them.

Second (and more important) - did you install a relay in the circuit?  If not, all of that amperage is going through your horn button and it is not made to handle such loads.

And yeah, the fuse is critical and should be as close to the battery as possible.

[Semper Gumby]

If you get the wiring diagram and trace the "HOT" wire from the battery you will find a significant amount of wire that is unprotected by a fuse.  If any of this wire becomes chaffed it will dead short to the frame.  You will find spot welds where this has happend.  This is a design feature of the BMW electrical system and makes it pretty rugged.

If you have any hot leads off the positive side of the battery make sure they are fused right there at the battery.

Do not run three or four feet of wire off the positive side of the battery powering *whatever* without there being a fuse right next to the battery positive post.

Good luck.

[Red_Hen]

Thanks Semper Gumby - great suggestion.

I'll remove tank this weekend and have a peek - having fuse closest to battery makes complete sense!!!

Rob: YES on relay and just a basic one tone air horn.  Horn wouldn't work w/out realy!

[tvrla]

Do not run three or four feet of wire off the positive side of the battery powering *whatever* without there being a fuse right next to the battery positive post.

It's not too likely this will happen before the starter motor. Starters typically take 150 amps - where are you going to find a fuse that big? :-)

Just make sure the positive lead to the starter is fixed solidly to the frame tube with zip ties to prevent rubbing.

All the other connections from the battery - like for the accessory outlet, or to the horn relay - it's a good idea to fuse it right there at the positive battery terminal.

[Rob Valdez 79 R65]

I got tired of messing with all of the extra wires on my positive battery terminal, so I installed a fuse block which also allowed me to have a separate fuse for each accessory.


_{click for larger}

Everything in the box is + voltage only.  The box is fastened to the frame with nylon fasteners.
I have a main 30 amp fuse leading into the box, which then connects to all 6 terminals on one side of the fuse block.
Then each accessory plugs into the other side of the block.
2 amp for my GPSr 12v-to-3v converter
15 amp for my horns
10 amp each for heated hand grips, accessory outlet and a spare.
And I still have one blank.

But I am still using the less-than-best ceramic fuses for the lights.

[Red_Hen]

Got to the R65 this morning.  Removed tank and re-routed positive wire from horn relay - fuse in line is closest to battery.  Checked connections and re-routed new plug wires that plug into coil.

Removed Shield and installed the (2) missing allen bolts that hold the diode board in place.  Discovered breaks in red & white/black wires that connect to stator - cut off old connectors, used shrink wrap tubing to seal the breaks & installed new connectors.

Hopefully, bike's electrical is in a better place. [smiley=vrolijk_1.gif]

[Rob Valdez 79 R65]

It looks like you found your problem.  Scary!

Another good reason to turn the engine over using the alternator bolt when adjusting the valves.  It makes you remove the front cover every once in a while.

[Red_Hen]

Rob,
do you think that's why I got the popping sounds - from the bare spots in the wire?  I know these bikes generate a lot of electricity.

[Rob Valdez 79 R65]

Rob,
do you think that's why I got the popping sounds - from the bare spots in the wire?  I know these bikes generate a lot of electricity.

I think that is where it came from, but I could be wrong.  There could still be additional worn wires on the main harness or elsewhere.
But the fact that those two wires were that badly worn and two of the four diode board mounts were missing makes me think that your bike has been severely abused over the years.