Backfire

[coaster]

Is it backfiring whilst running or just when being kicked over? If the later, low compression can cause this as the detonated charge blows past the rings. A simple compression check should eliminate this possibility

[Steveshipley]

it backfires very occasionally when running. seems to slightly misfire then bang. only very occasionally and unexpectedly, scares the scrap out of me. I'll be swapping the stator when I get chance. cheers

[coaster]

it backfires very occasionally when running. seems to slightly misfire then bang. only very occasionally and unexpectedly, scares the scrap out of me. I'll be swapping the stator when I get chance. cheers

My money would be n the LT coil in that case, CDI and pickups tend to just fail whereas LT coils, being made of a few thousand turns of hair like lacquer insulated wire are very prone to vibration and can fail due to the insulation breaking down or the actual wire snapping. The earth connection on the stator is also a problem point the riveted tag is loose. Also worth checking the integrity of all connections.