KEEPING IN TUNE

We’ve had a good few weekends on the ZX10-R, going right inside the engine to have a good snoop around. We found a few things in there that surprised and worried us, but they turned out fine in the end. First thing we did was drop a shim while checking the valve clearances inside the engine, straight down the oil drainage from the cylinder head – tink, tink, tink, it went, straight down in to the sump, well that's where we hoped to find it! We had to drain the old oil and take exhaust pipes off anyway, so we whipped off the sump and peered inside but we couldn’t find it! On closer inspection though, Ritchie found it nestling on the lip of the gasket just where the drain hole ends. Phew!

With the clutch drive assembly out of the way, and the drive sprocket removed…

…the whole gearbox just slides out; nice ‘n’ easy. Hmmmm, looks like someone has had trouble getting a sprocket nut off at some point though!!

Then we found a small ‘top hat’ when we took out the scavenge filter. Not knowing what the hell it was, or if we’d done something wrong ourselves, Ritchie looked at an exploded diagram in the manual, and found out that it was part of the shifter mechanism within the gear box. We knew then that the previous owner must’ve had the gearbox out and lost this small item. We made a note not to lose it as we took out the gears for inspection. Luckily the shifter arm hadn’t been damaged and the previously lost part sat nice and snug where it should’ve been, when we reassembled everything.

Next thing to worry us was the slackness of the chain that drives the oil and water pump. It was as slack as bicycle chain! We found out later that this was normal, a bit weird we thought. but to be safe Ritchie bought a new chain to replace the old one.

Gears looked almost new, no wear to be seen and tolerances seemed fine to us.

We measured the gaps between the gears and although we were unable to tell if the assembly had been shimmed, the gaps seemed within tolerance and there didn’t seem to be any wear at all. The clutch plates all measured within tolerance too and looked fairly new. We did find a thicker race-kit clutch plate in there, so it’s obviously been tweaked to suit the previous rider’s style on the slipper clutch. These things Ritchie will have to experience and adjust when we track test the bike, but for now it’s all looking fairly good.

We replaced the oil pump drive chain – the old one seemed a bit slack to us even though the tensioner was fine.

With everything back in and bolted up we started the bike and it ran much quieter than when we first heard it. Nice and smooth. Now that we’re satisfied with the motor, we’ll be turning our attention to the suspension starting with new seals and replacing the oil in the front fork and having the rear shock serviced.

After a successful startup and initial run, the next job will be suspension set-up.

We had a quick check measuring the sag and it looks like we’re going to need softer springs - front and back. Once that’s all done, we’ll need to find a track somewhere and give it a good run. Ritchie can’t wait, neither can we.

We’ll let you know when.

Bernie Thornton TEAM 71