POSTED ON ONE OF THE HAYABUSA BOARDS BY "DRAGZOOKS@INDY"

...great kit IMO

perfect for 5mm strokers and bigger
not only do i think the chain is tougher in general, but what i found most appealing was how well the chain stays on the sprockets when degreeing (and thus when running too)

if you've built any busa engines (esp. with big cams and stiff springs) you'll notice how when rolling the engine backwards the chain wants to roll up and skip teeth on the exhaust cam unless you crank the shit out of the tensioner (and then you can watch the guide flex to the point of ALMOST breaking sometimes)

granted...you should only take your readings while in the foward motion, but consider the cam chain during transients between decel/accel/steady rpm while running (ever watch a drive chain during a burnout and launch)

well with the roller setup and NO tensioner even installed...i could roll the engine fowards and backwards with out any chain lifting
so add in the properly adjusted cam chain tensioner and theres like zero chance of skipping teeth IMO

now its not necessary for every engine
but when you got a lot of valve spring pressure (exerts more stress on chain esp. when cam is getting valve off seat) and high lift cams it is worth every bit of its price IMO

now i will point out a few things for those considering it
if the splines on the starter clutch end of your crank are twisted MUCH at all...then forget it
the APE crank gear is an even more precise machined fit than OEM and it will not go without beating it on and risking shattering it

my OEM hi-vo gear would slide off by hand with only the ever so slightest resistance at one point
the APE gear i had to actually tap somewhat forcefully past that point and then it slid home freely (demonstrating the tighter machined fit)

there are modifcations to the front and rear rubber cam chain guides that must be done (nothing more than minor trimming with a sharp razor knife)
mainly at the bottom where they go into the cases around the lower sprockets
the roller chain is taller so the overall OD when wrapped around a sprocket is larger than the hi-vo when wrapped
after running the bike this year and disassembly this winter, i did find the chain "made" its own groove at the top of the rearward guide (somewhere i could NOT see any interference when assembling originally)

furthermore, since the chain is taller and the sprockets are slightly larger in OD (to get the 2:1 cam/crank ratio correct)you must eliminate the upper guide that rides on top/connects the two cams
optionally you may be able to trim enugh rubber off the bottom of it but it may tend to seperate when actaully in use
or you could space it up appropriately but then it hits the valve cover (tried that) and being magnesium i didnt want to undertake milling out a section and welding in a raised portion to cover it)
but it could be done if someone was deadset on running the top guide

i settled to just leave it out all together as i have done successfully on an 8mm stroked oil-cooled, oem 1100 WC gixxers and bandit 1200 merely come with a rubber deflector guide attatched to the vavle cover so to me it was a no-brainer

after looking at it all together, i accertained there is enough teeth in contact while "wrapped" around either came at any one given time to not worry about that top spacer (and other top builders confirm they leave em out too so i didnt loose any sleep about it)

damn, now that was a long write-up
hows that for a plug JAY

i figured someone needed to post ALL the details
"it takes some modifications" or "for experienced engine builders only"
which i agree, the novice builder might indeed run into problems

if so get ahold of me i'll help you thru it guy