S1 Publishing(Oxford)©2007

World of motorcycleS
S1 Publishing(Oxford)© 1999-07
 Maintenance - Engines
High Lift Camshafts
What is a high lift cam  A high lift cam has a higher cam lobe, which pushes the valve open a little earlier, and close later, and/or pushes the valve a little farther down, 

Profile of a standard cam lobe
(lobe in red)

A fatter lobe gives you a valve that opens faster, and closes later

A fatter and ligher lobe gives you a little more boost, but these need race spring kits.
What do high lift cams do?  As they open earlier, and close later, they allow a little more air/fuel mixture into the combustion chamber. This gives you a blittle more (or a lot) acceleration.  It also helps a little with exhaust gasses.
Is there anything I need do to if I buy one? You might have to replace the springs with some high lift cam, race valve kits are available for same machines
Anything I should know Yes, running your engine faster can make your engine wear out faster, so don't expect it to run for as many miles/Km's.
 I know that there are some different high lift camshafts, some will give you faster mid to high range power
 You might need to re jet the carb(s) sorry, I can't help you much on that, a dyno jet will let you know for sure.

This is just a general guide.
If you are about to do your own maintenance, using these pages, I take no responsibility if you get things wrong, fall off or blow up your engine!
& yes I can find you hi lift cams for some models but not as many as I'd like. some  cams be re profiled to spec. too
If you need info, let me know E mail me
Modified for 2009