Hi all,
I recently purchased a 1976 R90/6. It was working okay when I got it, but it’s developed a few quirks in the meantime.
It wasn’t exactly babied by the original owner, but a lot of maintenance was kept up (just never got washed). I replaced the battery since the old one constantly needed a trickle charger, but even before replacing the battery the bike won’t read that it’s in neutral with the green neutral switch not coming on with the other dash lights and headlights on. The bike and all the dash lights were working before. I pull the clutch in and CAN CONFIRM the bike is in neutral. Go to switch it on and I get no crank.
In any case, I know the battery is good, and I spent a lot of time trying to clean up near the neutral wire switch under the tranny (absolutely disgusting), but still no luck. I have no reason to believe it’s a starter relay/starter solenoid issue, but maybe I’m missing something.
Notably, the left carb will usually start leaking gas after 30 seconds with the petcocks in the on position, which is also very annoying.
Thoughts?
Like a lot of Airheads, your bike probably sat for a long while. The following article contains a list of the top 80% of the trouble spots that repeatedly develop during storage. If you have any questions, we're always here to help...
But I will highlight some areas to look at....
> 90% of starting interlock issues are in the switch next to the clutch lever. This switch actuates each time the clutch lever is pulled in, so simply put, it gets a LOT more action than the neutral switch in the gearbox. This switch is simple to test in-place with a Ohm meter.
> Dash lamps are a separate issue. That may have something to do with the connector on the rear of the gauge cluster, second guess would be the ignition switch itself. You may need a new KatDash insert. Further testing is required. ( https://katdash.com/ )
> A reminder here that the Gen warning lamp MUST be in the circuit for the battery charging system to operate. You must be able to turn the ign switch ON and see the GEN lamp come ON.... each time before you start the bike.
> If you have the under-tank brake master cylinder, then you MUST clean and inspect the the starter relay. This is a common issue on /7 bikes with the "mini-cube relay" and may apply to /6 as well. A "wellness check-up" is certainly in order.
After years of sitting on the side stand, caustic DOT4 brake fluid drips onto the starter relay (which is unfortunately located in precisely the wrong place). The relay itself not only controls the actions of the starter motor safety interlock, but FAR more importantly controls the flow of electrical power to the entire rest of the motorcycle. Not SOME of the motorcycle, but rather ALL of the motorcycle. The slightest issue with the mini-cube RELAY or its electrical terminal CONTACTS means the relay MUST be replaced. A thorough cleaning of the entire under-tank area around the starter relay is the place to start.
> I advise you to replace both floats and float needles with the newer ethanol-proof versions before going any further. This change will also allow the needle seats to be thoroughly cleaned. and float levels checked. You may also need the newer ethanol-proof diaphragms.
Hope this helps.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
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