www.zxrworld.co.uk

well, its known that these like to pop somewhere around 20k for alot of engines.

why is this?

is it a weakness in gasket design or fitting? or is it another reason as gaskets rarely fail of their own accord, for instance, the rover k series gaskets usually fail due to excesive head movement caused by plastic head dowels...

anyone know?

Your opening a can of worms here mate

Dunno if you have seen this thread

http://zxrworld.co.uk/zxr400oc/viewtopic.php?f=1&t=4633

Alot of views, some good points too.

No idea why it goes so earlyish, most bikes can go many thousands more with no problems. Must be a design issue if most engines go pop, however there are a few relentless engines that have gone over 40k with no problems so who knows?

yeah, ive seen that thread, im well aware that they dont *all* go at exactly 20k but it seems fair to assume most will go at some point in the engines life..

i was really wanting to know if theres a cause like a poor quality gaskets used etc...

i think its just one of them things mate, if it was a faulty design then they would all go at the same time wouldn't they?