ignition timing marks...

[mavis cruet]

i have been trying to check the timing on my 93 r100gs (electronic ignition i think) with a strobe. i can get the 's' in the timing hole (a tad low). when i increase the throttle it rises, but the 'z' that is supposed to replace it is no where to be seen. the bikes twin plugged and i know the 'z' should be a tad lower than central in the timing hole. do you think a tweak of the bean can will solve this? (dont want to faff tonight as in case i bugger things up as i need to get to work tomorrow) could it be the bean can is buggered? dont really want to buy one just to try as they're quite expensive. cheers in advance. karl

 

[Beemerboff]

It is electric ignition - the advance is still done by bob weights in the bottom of the bean can.

There is a small oval shaped inspection cover at the bottom of the bean can which can be prised out if you want a look at the weights, but the system is robust and usually trouble free. Most of the moving/sliding parts are nylon bushed- I dont think it is advisable to just spray release oil in the hole.

I have twin plugs on my G/S and set the timing by trial and error up a long steep hill . I have ended up only just able to see the S mark down below the timing hole so I wouldnt be too worried if the bike runs ok ,doest get too hot and has reasonable fuel consumption, I get around 20 km/liter

 

[mavis cruet]

cheers. bikes running a bit rough and just checking everything to narrow it down.

 

[Kenny]

You can always mark the position of the bean can ( electronic ignition )with a scratch from a screwdriver against the alloy face, then you can always revert it back to its original position

Good idea to try other theories re the rough running first...ie replace the HT leads/caps/plugs etc ( one by one and run it each time until the fault is found )

 

[Beemerboff]

Good advice - I have had two dud NGK plug caps recently, and on one the fault was intermittent and it wasnt until I failed completely that I found it.

Valve clearances can have a surprising effect too - easiest way to be certain they are equal is by feel , with the rocker boxes off and the engine running at a slow tick over.

Equal float levels are good too- check by measuring the depth in the bowl but only take one bowl off at a time, or the hose drains into the second one.

More obscure are things like the inlet stubs loosening in the head, carb needles in different grooves, worn throttle cables which just dont seem to stay in adjustment, old and stretched carb diaphragms, and the same on the head to carb hoses.

It will come good eventually!