The place to come to share your technical expertise, or just find out what the little springy thing is that's just pinged out of sight under the work-bench.
Basically a thunderace engine, carbs, airbox standard aftermarket filter.
Bike rides off on 4 no bother starting on choke etc Then will cut onto 3 after a few miles when you drop below 3k rpm then clear itself onto four above that.
Checked fuel line, tank is clean, fouls on no/3. changed all plugs good colour nipped up ht lead, cleaned bowls mains and pilot. intake rubbers all nipped up and good
any ideas?
I have had this issue not so long ago... It was one carb set much too rich, so rich that too much fuel for the spark to ignite. Once over 4k, the needle kicks in and superseeds the idle set.
