kawasaki cam measurements

My gpz550 cams are listed as 280 degrees duration...not getting
anything like that on a dial guage set up. ( I realise duration is
measured at the crankshaft so cam duration is doubled) Measuring at
0.040 " lift is the conventional way ,
does anyone know where kawi measure lift..I thought it would be zero
lift but seems not.

 

Without knowing the amount of lift Kawasaki uses when they spec 280
degrees, you aren't likely to get the same measurement.

What duration are you seeing at 0.040" lift?

The guy I bought my (sadly not mine anymore) '82 GPz550 from, probably
knows the answer off the top of his head. When he picked the bike
up brand new, he walked over to the parts counter and bought a head
gasket. The parts guy asked why he wanted one for a brand new bike,
he told him that he wanted to look at the combustion chambers when
he got home.

 

I'm about 40 degrees out consistently over about 10 cams, maybe I need
a dart tip in the dti guage as I have a roller ball type end which may
be too fat.