Here's a /7 brainteaser

[lrz]

Fired the Kaiser up for the first time this year. Battery was low (11.43v) from storage all winter, separate from bike, so I jumped it. Ran a tad rough at first but then smoothed out to a nice idle.

Pulled out of the driveway, 1st gear good into 2nd but just as I pulled in the clutch & started to blip the throttle there was a little "POP" and then...nothing. Not even any lights on the pod. Hmmm.

Walked/coasted it back, I always head UP-hill for the first ride, into the garage to have a look in the bucket where no fuses were blown nor wires come loose,etc. Stumped for a bit. I turned the bars a tad and, voila, the cluster is alight so I think broken wire somewhere and just as quickly it's lights out, w/out moving the bars at all, again!!

Now, I'm thinking-WTF? Played w/ the key to no avail. Walked away for a couple minutes to take a phone call, come back, turn the key and all lights are on.

So, I jumped it again and rode 5 miles or so to the local garage for the annual inspection. Other than having to jump it to get going homeward, the ride was uneventful; although it was exciting because, having recently re-lined my tank, I was running on a 1/3 gallon at best w/ a lot of hills in between.

I cannot fathom why the motor would quit & bike would be dead in the water solely due to a low battery, then run seemingly as well as ever minutes later?
Cobwebs?

[macdaddy]

" I turned the bars a tad and, voila, the cluster is alight so I think broken wire somewhere and just as quickly it's lights out, w/out moving the bars at all, again!!"

You answered your own question!Check and or clean the plug on the back of the cluster, look at the harness where it passes through the tripples. I bet you find your problem near there,OR you got rodents in your garage!?

[Garnet]

Loose or dirty battery connections. Bad ground wire(s) under the tank. Dirty or poor connections at the ignition switch. Check and clean the main + connectors at the diode board, the starter relay and in the headlight.

[lrz]

OR...
I've had the battery charging for the past 2 hrs, showed 13-something. So, I decided to see how it would turn over-it didn't. But I heard liquid leaking...
Battery is cracked.

I assume this is the problem?



The interesting thing is I placed it on a shelf in a heated space last Nov or so w/ no such damage...

Anyway, it was a Westco and actually was a replacement they sent out for one damaged in transit/delivery. So, ideas for a quickie substitute a la Autozone, NAPA, etc?

[Major Softie]

OR...
I've had the battery charging for the past 2 hrs, showed 13-something. So, I decided to see how it would turn over-it didn't. But I heard liquid leaking...
Battery is cracked.

I assume this is the problem?

Nope - a problem, but not the problem. That isn't a likely explanation for the sudden death and definitely not for the behavior when you moved the bars. It is only a fine explanation for still needing a jump to leave the mechanic shop.

You still need to do the tracing that macdaddy described.

[Deleted User 72]

OR...
I've had the battery charging for the past 2 hrs, showed 13-something. So, I decided to see how it would turn over-it didn't. But I heard liquid leaking...
Battery is cracked.

I assume this is the problem?



The interesting thing is I placed it on a shelf in a heated space last Nov or so w/ no such damage...

Anyway, it was a Westco and actually was a replacement they sent out for one damaged in transit/delivery. So, ideas for a quickie substitute a la Autozone, NAPA, etc?

Advance Auto Parts near me in central FL sells an AGM battery for our bikes with a decent warranty.

[lrz]

Actually, I just purchased an AGM-type from AutoZone didn't check Advance. We really lack MC-specific shops in this locale.

I should mention that I was informed: "oh right, the battery fell off the shelf once over the winter"...

It.Fell.Off.
?
!

Removing the damaged battery from the circuit seems to have resolved the aforementioned issues; we'll see what tomorrow brings.

The real deal w/ this machine is that I need to crosshatch the cylinders since my new rings don't seem to have seated -so it will be apart again before long.

[Ken in Oklahoma]

Removing the damaged battery from the circuit seems to have resolved the aforementioned issues; we'll see what tomorrow brings.

Nope. The Major has it right. I too regard the battery as not being the likely culprit.

Whenever I hear about a bike suddenly quitting, and the instrument lights going out, my first thought is the starter relay, or more properly the starter relay socket. The starter relay actually makes the connection between one red wire on the socket and the other red wire on the socket. That means that the connections there have to be good for the battery power to get to the headlight shell where it's switched and distributed to the rest of the electrical functions (including the instrument lights).

One could make a permanent jumper connection between the two red wires, which would bypass the potentially faulty connection of the socket. The under the tank master cylinder bikes are very prone to leaking brake fluid getting to the socket and creating a cruddy mess.

The problem you have is the possibility of riding the bike somewhere and having it quit at a farther distance than you want to walk or push the bike home. And I"m thinking that moving the bars might somehow jiggle the cables that might jiggle the wiring harness that goes to the relay socket.

I'm sensitive to the problem I've described because it happened to me on my own R100/7. To avoid being stranded I made a jumper wire, a "hotwire" if you will, from the battery positive post to the positive side of the twin coils under the tank. That would be the coil terminal with the green wire with some color tracer on it. (The negative side of the two coils is the black wire which goes into the front of the engine connecting to the points and condenser).

Of course, no matter where you problem might be, it's a good idea to clean up the socket contacts and the relay contacts.


Ken

[2valve]

hi to all, ignition switch contacts ? had some weird things happening when i first rebuilt my bike , ignition switch was to blame for it , even thou it was like the problem was in the loom , you could move the bars and the problem would vanish go for a ride and it would re -appear, new switch fitted and 15 years later all good !

[neil's 75/7]

A similar situation has occurred to me a couple of times, the most recent in peak hour traffic, between the cars, at the traffic lights and waiting to leap out in front on the green light. On the green light I dumped the clutch and then nothing. Bit embarrassing at the time.

Anyway, no electrics anywhere. Fuses intact. Battery OK. It miffed me for a couple of days.
After fiddling with cables, connections, relays etc. I found that there was a poor connection in the HAZARD LIGHT SWITCH that is mounted on the handlebars between the handle bar clamps. A bit of a clean-up seems to have rectified the problem.

Hope that my experience might be useful for you in solving your brainteaser.

Neil.