My 89 jap model had standard 110 jets all round which i have now changed for 115/118, along with the other suggested improvements in the carby section.
At the moment there are two layers of foam in my airbox, no air filter, looks like someone has cut away the old filter ready for a K&N but never completed the job.
The bike has a standard exhaust and i am looking for advice on what should go in the air box now? There is no sub filter either.
Standard Honda Filter?
Aftermarket Filter?
K&N?
Just the foam and see how it runs?

Standard honda air filter every time.

Hi, I've just got a couple a layers of hrc foam in my nc30, works fine. but a standard filter would eerr filter better.
Cheers
Ian