Hello all, Im working on a friends 03 Z400 she ran a stick through the rad.and her son unknowingly kept runnin it overheated evidently.He said he shut it down when the temp lite came on but who knows,any how put a new E-bay radiator in it last nite and its gettin water into oil.My question is do these have a seal or something behind impeller of the pump that would allow water into crankcase if failed or is the head gasket the only means of water entry? thanks in advance J.

 

Yes, there is an impeller seal that COULD fail. BUT.... more than likely you have a blown head gasket. You may even have a scorched piston/cylinder damage if the kid ran it until it seized!! Go ahead and buy a gasket kit and tear into it!! Good Luck!!

 

Thanks for your help!
We had it runnin after we changed the rad and it seemed strong so Im confident the piston and bore survived but I will check it out,thanks again for your help J.

 

I agree, head gasket.

 

Before you pull the head/cams, check your valve lash. This has nothing to do with your oil problem, but proper valve lash helps ease starting and idling. My stepson's Z started running rough and was hard to start. I checked and adjusted the valve lash and she now purrs like a kitten!! You will need a valve shim kit from HotCamms (about 50-60 bucks on E-bay), but you might get lucky and be dead on.

 

beware, when my motor got hot it cracked the cylinder instead of blowing the gasket, and then it ran like crap. so if its still running good then most likely its the head gasket, have the head checked for warpage when you have it off

 

OK ,thanks to everyone for their help! gonna pull it down today and see.