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I have a 79 engine (R100s) that was giving me ignition problems. I posted a while back about the coils/condenser/points/dyna booster leaving me stranded on the side of the road. I thought it was the fault of the booster but the symptoms started up again after I removed it. Coils are OK.

I decided to do away with any points or condenser issues and get the '79-80 (only) Boyer electronic ignition into the bean can.

As I was taking apart the bean can to remove the points and internals, everything inside was coated with oil.

It makes me wonder if the points could not send a correct signal because of the oil.

The black o-ring in the base of the bean can (that keeps debris/water out, and motor oil inside the case) looks fine. I wonder if it is possible for a small seal inside the cam that has failed? The parts Fiche show no parts for replacing the internals of the bean cam/cam.

Anyhow, bike runs fine with the electronic ignition on it. I took the bike for a ride around the block and it ran fine. I worry that a longer ride might cause oil to enter the can again and ruin the ignition.

Additionally the bean can has a high pitch squeal to it now. I wonder if that is because I sprayed electrical parts cleaner into the bean can to remove all the oil. perhaps I should spray a lubricant in there (if there is no engine oil in the can anymore)?

-Josh

There is no oil seal on the bean can shaft but it is not normal to see any real quantity of oil in there either. My guess would be that a PO has heard the squeal you mention and shoved in oil till it stopped... or else, there is significant wear on to the inner bearing in the bean can. A little oil will not affect the functioning of electronic ignition so I would be inclined to run the bike for a bit and see whether the oil comes back.

As you have discovered, spares for bean can's aren't generally obtainable and the BMW view seems to be that it had to be replaced as a unit. Some parts, like springs and plastic weight stops, have been made (normally by aftermarket suppliers) but if there is a problem with wear to the shaft and bush, the only real answer is to replace the can itself.

Rob

Many years ago I found a little oil in my points bean can. I suspect it was as much to do with excessive crankcase pressure I had at the time and has since resolved itself. The O ring has nothing to do with keeping oil from getting inside the can. Any oil inside the can will have got past the drive shaft. There are a series of washers at the back of the can which may be intended as a crude oil seal of sorts.

Not a pic of my can but it was the same.

How do you take apart that rear of the bean Can to access those washers? I tinkered with it for a while and couldn't figure it out. I'd like to inspect and clean it out...

jjwithers wrote: ↑Sat Jan 26, 2019 1:02 am How do you take apart that rear of the bean Can to access those washers? I tinkered with it for a while and couldn't figure it out. I'd like to inspect and clean it out...

It sure looks like a Bosch VW distributor in that area. See the pin that's been knocked out of the dog ring? See if you can get access to that with a thin punch, possibly through the notches in the body.

It's quite tricky... you need to drive the pin out and it is quite tight. The first thing to do is to remove the spring , This can be pulled off and out of the way with a small screwdriver (or similar). Looks more difficult than it is. You then need to support the drive dog in such a way that you can use a drift to drive the pin through... the recesses in the bottom of the can flange are there so you can get access. At the same time you need to support the body of the can so itself doesn't move around. A three handed job if ever there was one. Every time I do it, I swear I'll make up a jig to hold and support everything but I haven't got round to doing it yet. The pin needs to be hardened steel and the best I've found is as suitable sized masonry nail with the point ground off... mild steel will just distort.When all's said and done, it's fiddly but do-able.

Rob