Z1OwnersClub GB

Hi there

I have a Z900 and according the the manual and people I have talked to my engine seems to have an oil breather blockage. Does anyone know how I am best to resolve this please? I have changed the oil and filter, checked the breather pipes for blockages and everything seems clear, but the engine still seems to get very hot and more than it should do with smoke around the engine breather vessel. Does this need an engine rebuild or can it be flushed clear? Thanks again for any help and advice.

The engine only has one breather on the top of the crankcase behind the carbs and its simple internal baffle arrangement is unlikely to be blocked, especially on what appears to be a recent resto.
Removing the short cranked link pipe to the airbox will reveal the breather outlet bolt which can be unscrewed to determine any problems which it sounds you have already done.
Depending on mileage some smoke from the breather is normal and indicates ring/bore wear which may or may not be an immediate concern.
These engines do get hotter than you think so you may not have an issue .
You should perform compression, cam timing ,ignition timing and valve clearance checks to rule those out as a cause and also inspect the exhaust baffles to make sure they are not restricted and creating excessive back pressure.
Is this a bike you have recently bought, have restored or owned for a long time ?
Many "restored" machines on the market are simply cosmetic makeovers with the engines just being stripped, cleaned and rebuilt without refreshing any of the internals so depending on condition it may be due a hone and new rings at the very least.

As Zed1015 above has said.
Check valve clearances and then a Compression test. May need new piston rings.
Good luck

Thank you so much for your help that is great, really appreciate it. If I do need some further work doing on it, could you recommend anyone please? I am in Lancashire, near Lancaster. Best wishes Mike.

Check to make sure the strainer on the oil pump is clean & clear.

Thank you again for your help.

The bike when I bought it I was told the engine didn’t need a rebuild but looks like it does. Just struggling to find someone I trust to do it. Where best am I to find someone to do this ideally locally to me in Lancashire thanks Mike.


quote="zed1015"]The engine only has one breather on the top of the crankcase behind the carbs and its simple internal baffle arrangement is unlikely to be blocked, especially on what appears to be a recent resto.
Removing the short cranked link pipe to the airbox will reveal the breather outlet bolt which can be unscrewed to determine any problems which it sounds you have already done.
Depending on mileage some smoke from the breather is normal and indicates ring/bore wear which may or may not be an immediate concern.
These engines do get hotter than you think so you may not have an issue .
You should perform compression, cam timing ,ignition timing and valve clearance checks to rule those out as a cause and also inspect the exhaust baffles to make sure they are not restricted and creating excessive back pressure.
Is this a bike you have recently bought, have restored or owned for a long time ?
Many "restored" machines on the market are simply cosmetic makeovers with the engines just being stripped, cleaned and rebuilt without refreshing any of the internals so depending on condition it may be due a hone and new rings at the very least.[/quote]