can anyone help my mc18 is a bit tired now want to tune the motor, i have a 21 sp bottom end but wasnt sure whether to swap if this is possable or just fit the dry clutch/ gearbox. but would really like to go for a total rebuild. ( been out of the nsr scene for a bit, does anyone do 18 crank rebuilds yet ?

I'll be interested in what you can find out, im just down the road for you in medway. Im sure stan stephens whose local can supply parts for a rebuild

ill see what i can find out it was the crank i was thinking of, start afresh when you tune it

This has been discussed a lot here .
***** here in australia will rebuild mc18 cranks for around $600au
There is a place over there that advertise on e-bay can`t remember the name .
I would prob use the 21 bottom end as new cranks are available . With the 18 barrals that flow a bit better.