www.zxrworld.co.uk

Should I be wary?
what sort of miles should i expect before an engine rebuild etc etc presuming all the work (cam chain etc) has been done at the right intervals?

Hard to say really, if a motor has been going for that many miles trouble free i expect there are many more to come. Off the top of my head the highest mileage motor ive heard of for a ZXR is about 64K miles. Long as you keep good oil in it, warm it up before you ride and maintain it it should go on and on. Only thing that i would imagine that would go after the cam chain and headgasket are crank bearings, but long as you keep good oil in it they should be good for alot longer.

my first ZX-4 did over 100,000 miles on the same engine, head-gasket went twice, 20k, then 60k. Other than that it was fine .. oil/filter were changed religiously every 3-4k though. and it didnt die, it got nicked !

Em's current bike is touching 60,000 miles on its original engine.. head-gasket went at 25k, and it ate a couple of tappetts at around 45k .. still runs sweet.. still puts 135 on the clock .. again, its had regular oil/filter changes, and we've had it for 5 years (8000 miles old when bought, and actually, it runs better now, than it did then !)

i have blown a big-end up.. but that was after a rather nasty crash which had holed the cases letting all the oil out .. guess the damage was done in the few seconds before the engine stopped spinning as it seized itself within 200 miles of being put back on the road.

so, yeh, regular maintenance is the key

ok we have a new record!!! 100,000 miles!!!

Well there you go mate, hope that answers your question

yes it does, thank you very much