Ignition Timing

[Nige1100s]

First of all I apologize if Im usig a lot of limey jargon in this post.

After my recent engine rebuild I reset the ignition timing statically using a buzzer to show when the points open. I set them to the T mark 5 degrees BTDC. The bike started well but ran a bit odd when accelerating.

I then used a timing light to check the dynamic timing and found that no matter how slow i set the idle the thing was no where near the static timing mark but about half way up the advance curve. A little bit off idle it went to full advance and then given more revs it went well beyond the full advance marks.

My first thought was weak advancer springs allowing it to advance on idle but this didnt explain why it would go beyond the max advance.


I took off the advancer and checked it against a spare. There was no real difference. I cleaned it all up and checked the range of advance which was bang on40 degrees.

I have now set the timing at max advance at high revs and it comes back to the static position at idle. If i check it with the buzzer it shows a static timing of between TCD and 2 degrees ATDC.

Leaves me questioning why the static timing and dynamic timing are so different. I have had problems in the past with cars with worn distributors but having the points on the crank eliminates most of the places you get wear or backlash. Could be someting to do with the shaft lifting as it runs? Any thoughts?

By the way i think the acceleration problem was mid range richness because by lowering the carb needle it cleaned right up.

[Nige1100s]

I just put in a new set of points today, couldnt see any problem with the old set. But setting these to the T mark and then checking them with a strobe light they run up to full adavence when i rev it and dont go any further like the last set did. I cant understand whay but it seems to have solved my over advancing problem.


Thanks Samfor the offer of help but i didnt realise id got a message.