starter issue

[dave_A]

Hi, I'm new to the forum, apologies in advance if this issue has been covered previously. I have a problem with the ignition/starter motor system not disengaging on my 1971 R60/5. Pressing the starter button, the starter motor engages but won't disengage, even after letting go of the starter button and removing the key from the headlight unit. The starter motor keeps going until the battery runs flat. I have removed the starter motor and bench tested it - everything seemed to check out, it works as it should. I reinstalled the starter motor and the bike started as normal for a very brief period but then the problem returned, as soon as I connect the battery terminals - after recharging the battery - the starter motor kicks in. A few years back the starter relay failed and I replaced it with a generic relay - that set up's been working fine until now, I don't know if it's related to my current problem. Any advice is greatly appreciated

[SteveD]

Maybe that generic relay is stuck. Give it a whack and see if something changes?
Solenoid stuck?

I seem to remember the ignition switch might cause this too. Dragging my memory though and don't bank on it!

Does it have points still?

Willkommen, by the way!

[gspd]

Your switch (starter button) or your starter relay is probably faulty. Small possibility is that the solenoid itself is faulty, but that type of failure is quite rare. Pull the black wire off the starter solenoid terminal and assure yourself that the starter works normally when you jump that solenoid terminal to the battery positive. The starter button and relay can be tested with a simple test light. No fancy equipment needed.

[dave_A]

Thanks for these, I'll check the starter button and the relay. I let you know how it goes.

[Rob Frankham]

In passing,

When you replaced the start relay, you say you used a generic relay. Was this specified for use as a starter relay or just a normal accessory relay. The starter circuit draws a considerable current and a the OEM relay is rated at 60 amps. An ordinary accessory relay is probably not powerful enough and can weld itself shut. Doesn't need to be an OEM relay but it does have to be rated at 60 amps...

Rob