Broke down on way home from Work today...

[tvrla]

Our bikes use solid core plug wires. Unlike cars that use some sort of carbon stuff that breaks down within miles, ours will conduct electricity almost indefinitely. But the insulation doesn't last indefinitely, and gets hard, brittle and cracked. Then when it's damp, it's possible for the spark to leak out and find an 'easier' ground than jumping the spark plug gap.

The caps on the stock plug wires can also develop high resistance, and because they're molded on, there's nothing that can be done about that.

Sure, they can be resistance checked. First take a measurement from cap to cap - I've forgotten what the reading should be, but what surfaces is something like 17K Ohms or something like that. There should be 5K Ohms in each cap, plus the resistance of the leads, plus the resistance of the coil.

Or you can pull the wires from the coil and test them individually - they should be around 5K Ohms for the electronic ignition and 1K Ohm for points.

[Barry]

jg928s4

If your 1980 R65 has the original coils they will be twin 6volt type which should measure 1.5 ohms on the primary winding and 7000 ohms on the secondary winding.

For example I have 5000 ohm caps so cap to cap I measure 24000 ohms (5000 + 7000 + 7000 + 5000).

It's more useful to measure from cap to earth which will show any differences side to side. Here I get 12000 ohms (5000 + 7000). If you measure both sides and they are the same somewhere between 8000 - 12000 ohms depending on the cap resistance then the probability is everything's fine. If you get a substantially higher figure you need to detach the leads from the coils and measure everything separately. If your lead and cap together measure much more than 5000 ohms bin them without a 2nd thought. Ideally you need to know what the caps are supposed to be. They should be 1000 ohms for a points bike but as these are not that readily available many people have fitted 5000 ohm caps intended for the electronic ignition models. 5000 ohm caps if not ideal work OK on a points bike but you should not use resistor plugs as well.

[Rob Valdez 79 R65]

Ideally you need to know what the caps are supposed to be.

And I don't think the caps can be removed from the wires on either type of OEM set-up.

[Barry]

And I don't think the caps can be removed from the wires on either type of OEM set-up.  

Ok so that means you would have to remove the lead from the coil for testing and if the lead and cap together read substantially above 5000 ohms I'd replace them.

If you do replace them it's cheaper to make your own.
I have solid copper leads and NGK LB05F caps which are 5000 ohms. NGK caps are readily available and very well regarded. For a points bike if you can get LB01F caps which are 1000 ohm so much the better. Someone posted recently that they were available from an XS650 web site in the US.  

[Rob Valdez 79 R65]

The reason I buy the NGK 5000 ohm caps (for my points bike) is because I perfer the connection method of slipping over the threaded top of the spark plug rather than the cap that comes screwed onto most spark plugs.  It just seems to me to offer a better connection.

                   5K                                                              1K



And they offer this smaller non-resistor cap if you want to go crazy:


Not sure how well it would fit.

Images courtesy of http://www.mikesxs.net/products-27.html#products

[Bob_Roller]

If you go for the non-resistor caps, you don't have to get concerned about non-resistor plugs, which can be a bit troublesome to find at times and just use the common main stream resistor plugs available anywhere  .

[jg928s4]

Got hotter plugs (NGK) from Local autozone,   Puff of smoke out of exhaust, bike starts, then dies, now no electrics. Headlamp or anything.  Dead.  Blow a fuse?  

[Bob_Roller]

Headlight isn't protected by a fuse, it's direct wired .

I think I would start looking at wiring, the  cables at the battery have caused problems, with corrosion under the insulation, terminal ends still tight on the cable .

How does the end of the negative cable look where it is bolted the transmission case

The ignition switch is a remote possibility .

On the positive terminal of the battery, there are two wires, one is the large diameter black cable, the other is a smaller red wire, this wire provides the power to all of the circuits on the bike, except for the starter .

How does the terminal end look ?

[jg928s4]

Have battery on a Tender, it is full charge.   Can I bypass Ignition and Kill Switch to see if they have been the culprit?   Before this try my starter always turned over w/Plenty of Zest, now no power to it at all...?

[Bob_Roller]

You can remove the wires from the ignition switch and tape them together  for testing purposes, you don't need to put the green wire in the group, it just lights the "Parking" light under the main headlight bulb, when the key is in the "PARK' position .

The red wire at the ignition switch is direct from the battery, so unless you have a battery cable disconnected, you will have battery voltage there when you start working there .

[jg928s4]

Pulled a Kill switch from the spares bike, before putting on the bike I reseated the ignition connector and have power again.  Must have pulled it part way out when I buttoned everything back up las weekend.  Have power again, bike pops wants to start, has what I would consider good white spark on each plug.  Is there a possibility the timing could have slipped?

[Bob_Roller]

Anything is possible with a 32 year old vehicle .

Not difficult to check, there's a timing port hole on the left side of the engine, should have a rubber plug covering it .

[tvrla]

Have you considered the condenser? It's beginning to sound like that could be your problem. Condenser problems can mimic just about any other fault on the bike. They've driven me crazy more than once.

Easy to test - just remove it from the circuit. The points will wear quicker, but it will run, and get you home.

[jg928s4]

Running ! ! , But not as good as before yet.

Disconnected condensor, stopped trying to Fire.  Took a look at the points, apeared ok, but reset gap at .016 feeler, no difference in desire to start.   AS I was in there I notice a PO paint dab where the dwell was set before?  So I cleared wires etc. and loosened the Bean can and shifted Dwell to previouse setting, it had not shifted, semmed very tight before loosening.  Try to start Bike at new setting, it starts up! seems rough but running, I adjust dwell by sound turn back to where I had previous, full lock clockwise and it idles good.  Burn Arm on Exhaust.. put front cover back on, will not start?  Take off cover bang knuckle on Shock, add oz of Blood, Bike starts ? ?  Notice condensor wire that goes to coil has/had been pinched and is quite brittle.  Replace w/cable from parts bike, starts and runs.   Button up bike.  Go for a ride, idles good, but does not give good power and pops and sputters....    Reminder always add blood..

[tvrla]

I'll remember next time to add blood. Maybe you've got a particularly blood thirsty specimen on your hands...

I'm thinking you may have disconnected the points lead when cutting the condensor out of the circuit.

Well, no matter now since it is running and it sounds like you found the fault. At this point it just needs the dwell and timing dialed in to run as sweet as before.