28-07-23, 10:38 AM
This follows on from my post on cylinders 3&4 not firing. Managed to get those working by replacing the plug caps. Now I have a new problem!
When riding for a bit at high RPM/speed (5-10 mins at 70+ MPH), the bike starts to stutter, which will turn into a misfire if I carry on. Then after a few mins at low RPM/speed the misfire/stutter goes away.
I previouly took off the carbs and cleaned a load of gunk out of the float bowls and jets (didn't touch anything else).
Things I have tried/checked:
When riding for a bit at high RPM/speed (5-10 mins at 70+ MPH), the bike starts to stutter, which will turn into a misfire if I carry on. Then after a few mins at low RPM/speed the misfire/stutter goes away.
I previouly took off the carbs and cleaned a load of gunk out of the float bowls and jets (didn't touch anything else).
Things I have tried/checked:
- Checked for kinks in tank breathers and fuel line.
- New fuel filter - previous one was installed backwards so couldn't see if it was blocked. It wasn't.
- New sparks.
- New spark caps (NGK straight) - Cut 10mm of the HT leads before installing
- New (2nd hand) regulator/rectifier.
- Checked coils - primary resistance out by .5 ohm, secondary resistance well in spec.