R80 electrical problem

[luckro]

Hello my friends,

I'm currently in northern Peru labouring my weary brain cell with an electrical issue relating to my R80. It's running but the electric start sometimes thinks twice before working. Also, today the engine cut out while on the move. Because it didn't bump-start while coasting, my best guess is that there's a short circuit relating to the engine kill-switch.

I've found no chafed wiring around the steering column and the bundle of earth wires under the tank are fine. And so I have resigned myself to a full investigation with the dreaded multimeter. Before I do, I was wondering if any you wise wanderers knew of common gremlins (e.g. starter relays, the starter/kill switch . . .)

Thank you!

Bob

[Warin]

I have come across one traveller who had no alternator charging - starter motor stopped due to low voltage .. later the engine stopped due to low voltage ...
So basic question .. when you first turn on the ignition .. do you have TWO red lights? One is for the oil pressure - the other for the alternator/battery. If the alternator/battery one is not working you may not have alternator charging the battery.
If the battery voltage measured with your multimeter is low (less than 12.5 volts) then .. charge it ... then check for sparks, charging ...

Engine kill switch will turn off the instrument warning lights (as well as the ignition) .. if they came on when the engine stopped .. it aint the switch.

[luckro]

Thanks for the reply Warin. Both red lights light up, the battery one going out with acceleration so battery is charging. Also, if the ignition doesn't work with first press, the second comes full power. Still, I'll check the voltage tomorrow. But I think it's something else.

The engine has also 'coughed' occasionally over the past few rides, where the engine cuts out for a lurching moment, again while on the move. I thought it was rough fuel, but now believe it's the same electrical issue.

Cheers,
Bob

[Moto Phoenix]

From your description it sounds to me like one of two things. 1. Start with basics, check battery terminals are clean and tight. Also check the battery - lead is tight at the connection on the gearbox. The + lead goes to the starter solenoid so that is harder to check and I have rarely seen these come loose. If you do check it make sure you disconnect the - lead first to prevent shorts with your spanner on the engine casing. 2. If the kill switch is electrically dirty this could also cause the symptoms you are getting. Sometimes vigorous operation of the switch back and forth for a minute may restore the internal connection. Failing that you could find the connector block coming from the switch inside the headlamp, disconnect it and bridge the wires on the block going into the loom to restore the circuit. If you do this you will loose the kill switch function, since you have effectively taken it out of the circuit. Check those and see how you get on. If you are still stuck I'll try to help. Good luck, Guy.

[Threewheelbonnie]

Check the earth. -ve battery post to frame, swingarm, forks etc. No resistance.

Andy

[mark manley]

Also check the condition of the alternator brushes and the condition of the slip rings on the rotor. If the brushes are about 60-70% worn which means they are disappearing inside the plastic casing they need replacing, if the slip rings are dirty they can be cleaned with scotchbrite.

[Warin]

Suspects so far;

The alternator - as the light is working correctly I'd think that is ok.

The kill switch will make itself evident by the instrument warning lights not working.

Possible loose wire from battery to starter motor (and return to the battery negative terminal).

All possibilities, needing carefull thought by the op to think about the symptoms and getting them to match the results of the above problems. More testing and information may aid analysis.

[luckro]

Guy, Andy, Warin - thank you!

I'll take a closer look today. 1st coffee.

The year of the R80 g/s is 1981.

Anon,

Bob

[Moto Phoenix]

Bob, if you require further assistance it would be useful to know the year of manufacture.

[luckro]

Ladies & Gents,

In the name of completeness I thought I should report back with the elusive culprit. It was the ignition trigger, otherwise known as the bean can in the front of the engine, where on earlier models there were distributors. I was reading up on Robert Fleischer's site (Snowbum, the man who knows far too much), how there are several things which can cause strange intermittent electrical problems whilst the motorbike is moving:

1. Dodgy/dirty starter kill switch. Not in my case.

2. The coil, which either dies dramatically, or can sometimes die a slow death through a short circuit in the second coil. I replaced mine, but that wasn't the problem.

3. The bean can, the original of which is part electronic, part mechanical. A transistor inside of it called the Hall Device is the part which tends to fail, especially with temperature changes, especially when hot, while operating perfectly when cold. The cut in power can be just seconds, as was the case with me. He described it as a stumbling in the engine, which is exactly right.

Carlos Arias, a fine mechanic in Quito who also owns an R80 (a lovely miracle), came to the same conclusion and helped with fixing it.

So I bought the hopefully new and improved fully-electronic part made by Siemens from Motorworks, along with a new ICU (ignition control unit) which fits under then fuel tank, since they're replaced together. So far so good. It still stutters a bit when in 4th or 5th gears at low revs, but I think that's because the timing has shifted slightly and needs doubling checking, but it's no longer stumbling or cutting out.

Thanks all of you for your support. All the best,

Bob
Cali, beloved Colombia