Main Motorcycle: Rickman T120
TE Lifetime Contributor
Join Date: May 2010
Location: Victoria Australia
Other Motorcycle: T160,TR6
I'm sure there are other reasons for moving the filler cap to its lower position,including the likelyhood of oil sloshing out the oil tank breather tube under braking and then being fed to the crankcase breather hose.At best,it will end up in the chaincase and temporarily raise the oil level.At worst,it would be blown out the breather hose.
There is not much to gain by increasing capacity,except a longer mileage between oil changes.The oil tank temperature is normally too cold,and an oil heater would be more appropriate than an oil cooler.
Any amount of oil added above the return outlet will surely seep back through the rocker spindles and flood the crankcase.No-one wants an extra litre of oil in the crankcase.
I'm sure Triumph deliberately fitted a hot intake cam to the T140 to reduce low and mid-range torque.It was then retarded,to make the engine more gutless below 6000 rpm.The exhaust cam duration was less than ideal above 4200 rpm,so you lost at both ends of the rpm range.
Overlap didn't change much,so the engine still idled OK.