Further to my earlier post re a theory I read about smaller idle jets curing a bottom end stumble :
Finally got around to fitting the smaller idle jets. The originals checked out as 41 and it idled well on them with the air screws 1.1/2 out.
The new ones are stamped 36 and checked as 36. Had a run this afternoon and it idles well (again at 1.1/2 out ) and carburates clean the whole range. No off idle stumble and even pulls clean from low revs in a high gear.
In short, it runs perfect.
It seems illogical, but it works, it's now a pleasure to ride.
Less is more !
