adjusting the bean can

[Mike the Bike]

Hi

I've just done a top end overhaul on a '91 R80GS. When I removed the bean can, I forgot to mark it for repositioning later. The Clymer manual says I need a special tool to set it up again. Is there any way of setting it in the correct position without the BMW tool ?

Many thanks

Mick

 

[Kenny]

Are there definately no wear and tear markings that may help it line up...even near to the original settings will be enough to start the bugger..then obviously move it a little at a time to get near to some semblance of normality..finish off with a timing gun

 

[slowkitty]

I note the reference to a timing gun ... is that no other way without that?

Cheers

 

[Beemerboff]

The unleaded juice that is around today burns a bit faster than the stuff that was around when BMW marked the flywheels, so it is debatable if the marks are in the correct spot anyway.

As a rough sort of setting turn the bean can with the engine running below 1200 revs until you get the fastest tickover - this will be too far advanced but mark the spot as you dont want to go there again.

Retard the timing slowly which will slow the engine down - stop at the point where the engine just doesnt sound right.. Mark that point, and the best point will be about 3/4 of the way back to full advance.

I didnt know where to set the timing my twin plug high comp 1000cc G/S so I took it to a dyno tuner, and that was how he found the spot for the first run.
It didnt change much after the subsequent runs.
It was also pretty close to where I got it just doing test runs up a long steep hill. Looks like about 26 degrees if anyone is wondering.

 

[Mike the Bike]

Cheers all - I'll go with the Beemerboff plan .. doesn't involve buying anything !

 

[Steptoe]

Spark plugs out and resting on the cylinder. Engine in gear and ignition on. Beancan bolts hand tight.

Turn the engine over by hand using the rotor bolt and look/listen for the spark plug to spark.

Check it sparks in line with the static timing mark in the timing hole.

Move the beancan to adjust so that it sparks when it should. Tighten beancan

 

[Mike the Bike]

Even easier - thanks Steptoe

 

[Beemerboff]

That used to work with points but I have never tried it on on electronic ststem.

I found it easier to set the engine position and then turn the distibutor till you got a spark, but as I said I havent tried it on a Airhead.

Aim on the side of retarded - unleaded burns 2 or 3 degrees faster than leaded.

 

[LivNorway]

I was wondering why it is so important to put a beancan in correct position on a motorbike; normally I put all my food in my sidecar.
But a little Googling helped me!

I learn a lot from UKGSER. Thank you, members!

Liv.

 

[Bill-H]

Spark plugs out and resting on the cylinder. Engine in gear and ignition on. Beancan bolts hand tight.

Turn the engine over by hand using the rotor bolt and look/listen for the spark plug to spark.

Check it sparks in line with the static timing mark in the timing hole.

Move the beancan to adjust so that it sparks when it should. Tighten beancan

Why does it need to be in gear?

 

[Steptoe]

Why does it need to be in gear?

My fault - i was going to say turn the engine over by hand at the rear wheel. Then realised the front engine cover would be off anyway fitting the beancan so changed my mind and said turn the engine over by the rotor bolt, but forgot to delete the "in gear" suggestion.

 

[Bill-H]

My fault - i was going to say turn the engine over by hand at the rear wheel. Then realised the front engine cover would be off anyway fitting the beancan so changed my mind and said turn the engine over by the rotor bolt, but forgot to delete the "in gear" suggestion.

I'm disappointed now, thought it was going to be a special Steptoe magic solution.

 

[Mike the Bike]

Hi all - I've tried the technique of .. ignition on, spark plugs resting on head, turning over on rotor, but no spark no matter how many times I turn the rotor (but it does spark freely if I spin it on the starter).

Am I doing something wrong ? ... cheers

 

[Rob Farmer]

I'm disappointed now, thought it was going to be a special Steptoe magic solution.

They usually involve a collection of big hammers and calling somebody a cahnt.

 

[Mike the Bike]

Hi all - I've tried the technique of .. ignition on, spark plugs resting on head, turning over on rotor, but no spark no matter how many times I turn the rotor (but it does spark freely if I spin it on the starter).

Am I doing something wrong ? ... cheers

Any ideas anyone. I'm concerned that maybe I've got the valve timing all wrong now, having replaced the cam chain (I lined up the dot and arrow on the respective cogs for the cam chain, as per Clymer manual). I think everything may be 'out' by many degrees !

Cheers

 

[Bill-H]

Any ideas anyone. I'm concerned that maybe I've got the valve timing all wrong now, having replaced the cam chain (I lined up the dot and arrow on the respective cogs for the cam chain, as per Clymer manual). I think everything may be 'out' by many degrees !

Cheers

someone will be along to correct my shortly if I'm wrong, but make sure BOTH plugs are earthed to the heads, as I think that while the one is generating a spark, the other acts as the earth - seem to remember reading that somewhere.

 

[Mike the Bike]

Thanks Bill -I'm getting a spark now. Problem is, spark occurs nowhere near the timing marks on the flywheel (no matter how far I twist the bean can). I think I need to look at the cogs on the camchain ? Unless there's someting else I'm missing ?

Cheers

 

[Mike the Bike]

Fixed ! The cogs weren't aligned (I was sure I did it OK 1st time). Doing everything for the first time takes a lot longer than some of you seem to take. Simply putting the split link on the cam chain took about 2 hours of cursing.

They are really simple machines though - next time I'll be a lot slicker. Trouble is, I'll have forgotten the technique again by that time.