Bike cuts out while riding

[Bobn]

BTW, a possible easy fix is to stick 1/2 litre of Isopropyl Alcohol in the tank at the next fill up. The IA mixes with water and will be burnt through the engine in the normal way. You can get IA from your local Pharmacy. It's also excellent for degreasing parts prior to gasket fitment.
It's deadly poisonous by ingestion in case anybody was thinking of using it as a mixer....

[ianrg]

Well the problem is still there after carb removal and refitting. Checked fuel tank breather - fine. Ran ok for about 20 miles and then just died without warning again. It starts up again no problem.

I'm on the verge of ordering a new CDI unless anyone has any other ideas that could be worth trying first.?

[switch]

Check the impedance of the crank sensor - both cold and warm. I remember such a problem a while ago. Without proper crank input even a good CDI doesn't work.

[ianrg]

Thanks to all who replied - have replaced the CDI unit and the bike is now running like a dream!