Timing changed by itself?

[Johnny J]

My bike has been quite easy to start and has run good, but after a longer trip (300km) last weekend it doesn't any more.
Now it kicks back quite severly, takes more kicks to start and pings alot.

Guess I have automatic timing, (GF 1960) what could have happened?
Can it change to more advanced timing by itself?
What else could have influenced this?

[bsa-bill]

Possibly stuck open (in advance), broken spring or springs, or fibre drive gear has stripped a cog or two and it's moved the timing

[orabanda]

I had a similar experience; the lock nut on the points loosened, and the points gap had increased - check points gap is 0.012" - 0.013"

Richard

[Greybeard]

I had a similar experience; the lock nut on the points loosened, and the points gap had increased - check points gap is 0.012" - 0.013"

That's my guess also.

[Johnny J]

OK, thank's guys, will check this as soon as my back pain has eased of a bit. 

[morris]

OK, thank's guys, will check this as soon as my back pain has eased of a bit. 

Don't tell me the kick has hit you in the back...?? 

[Johnny J]

Yeah, I was sitting on the footpeg and leaning back rapidly to start it. ;-)

No I have had this back problem for some time now, sucks...

[Johnny J]

Anyone familiar with how to adjust these points?

[Greybeard]

Loosen the screw and the baseplate can be moved allowing the points gap to be set.

[Johnny J]

Thanks!

Is it normal that you can turn the plate (or is it the whole inner of the magneto) by hand a few degrees left and right or should it be totally rigid?

[Greybeard]

If you have an automatic advance and retard unit the magneto shaft will move a few degrees as the weights are forced out. The points base-plate must not move in relation to the magneto shaft.

[Johnny J]

Seems like adjusting the points did the trick, it started on the first kick!
The point were too close, took them to 0.012".

[Greybeard]

Remember that the points gap affects ignition timing: Too close and the timing will be late, (retarded). Too wide and the spark will be early, (advanced)

[Johnny J]

Yes, I will see how it runs in a couple of days, especially when warm.
Have to stuff myself with pain killers first... 

[Triton Thrasher]

There's a little oil wick in the cam ring.

Some light machine oil on it might slow the wear down.