exhaust port opens 25.5mm from tdc 93.75 ATDC dur 172.5 degrees
transfers open 34.8mm 122.15 degrees ATDC dur 115 .7 degrees
blowdown = 28.4
am I right in saying ex port tuned for 9000 rpm but transfers tuned for 7000 rpm?
ok maybe size/width/shape comes into it.
few yrs ago I messed around with porting plus a diy pipe on my rd350A and at one stage ended up revving to 11400rpm with nothing below 7. horrible to ride unless you were drag racing.
this bike I would like max power around 7000rpm with loads of mid range torque to make it easier to ride
having 4 gears helps.
ive worked out at 7k my pipes tuned length wants to be over 1 metre but not many pipes on the market seem that long.
ive been busy looking at port maps/port jobs last few days and seen some swiss cheese jobs. I would like to buy another 73 cc top end and play around with that one day.
but the goal for this one is for 30mile cruising at 45-50mph if possible.
what have people found to be a safe ignition timing setting?