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Topic-icon 80/RT Intermittent spark, what do I look for

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4 months 2 weeks ago #4769 by Wobbly

82 wrote: I have cleaned all the terminals on the starter relay...

Very sorry to keep hammering topics... but mechanics can't be successful and do the same job 2 or 3 times, so successful ones tend to be OCD about details. This will seem obsessive to the average owner-mechanic, but that's simply where I'm "coming from".

Due to the short comings of this forum style of diagnosis and repair, which is not many words and fewer photos, please forgive me if I suggest 2 more things about that relay... 1) pop the plastic top off and inspect the condition of the electronics on the inside, and 2) coat the 5 terminals with NO-OX-ID before plugging it back in. Go ahead. Humor my OCD side. :P

82 wrote: ....when the engine quits nothing else seems to be effected, lights etc all work and there is no dimming, just the ignition cutting out and the bike quitting.


And just so you know... I agree with your logic, the starter relay cannot be the entire issue. I think we can also rule out poorly contacting fuses since the 1983 ignition doesn't seem to be fuse protected.

So the only other major circuit item remaining is the key switch and the connection inside the headlamp shell. I want you to do 2 tests:
Prep
► Remove the tank and inspect the terminals and condition of the short wire than connects coil #1 to coil #2. Unplug both wires, treat both terminals with NO-OX-ID and plug them back in.

► Blue/Green from the handlebar switch and the main harness meet on the multi-color terminal board in the headlamp shell. Unplug both wires, treat both terminals with NO-OX-ID and plug them back in.

Tests
► Clip a test lamp between an engine fin (ground) and the Blue/Green wire (which has been disconnected from the #1 ignition coil), and turn the ignition switch to the ON position. Jiggle the key back and forth in the ON position. Wiggle the wires on the rear of the ignition switch (especially Green). Flex the harness going to the handlebar switch with the Kill button, flick the Kill Sw, and flex the main harness going back to the coils. Wiggle the Blue/Green wires inside the headlamp shell. The test lamp should never flicker or go OFF.

► Before reinstalling the fuel tank, do not plug the Blue/Green wire back on the coil. Instead make up a test lead to go from the coil up to the Red on the rear of the ignition switch, or any Red wire (like on the clock). This will by-pass the ignition switch and the Kill Sw. Be ready to ride when you plug that in because it's like turning the ignition ON. (You'll also need to turn the key to get brake lights and head lamp. ) Then go for a ride.

I bet you'll find something.

Don't hide 'em, Ride 'em !!
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4 months 2 weeks ago #4770 by 82
Having done most every thing I could think of my logic was that the only thing that had not been cleaned or replaced was the hall sensor bean can, I took it off and found a crack in the wire coming out of it to the 3 pin connector to the ECU. there was a tear in the outer covering for the 3 wires and a crack in on of the inner wires, did not appear to be a break in the wire. as these wires handle very low voltage I suspect there was variable resistance on the wire. don't know if the wire was the cause or if the hall sensor was giving up but rather than risk a repair to the wires I replaced the bean can with a rebuilt one from european motoelectric and so far the issue is solved.

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4 months 2 weeks ago #4773 by Wobbly
Motorrad Elektrik sells a new, better connector on a pigtail. You can easily add the pigtail to your existing bean can.

Don't hide 'em, Ride 'em !!
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