Z1OwnersClub GB

I think my worst case scenario has just been confirmed. After a few weeks of rough running and smoke from n0 1 cylinder, i thought it might have been a carb problem.
But oil coming out of the exhaust drain hole, oily plugs, and I think a valve seal has give up, more annoyingly on a rebuilt engine with 300 miles on the clock. The head was overhauled but not with Genuine Kawa seals, and I think this the problem.
What are people's thoughts???? Especially on the seal issue,,, has it ever happened to anyone else.
All the symptoms are there, excess smoke on start up, on idle, and under acceleration....
Another job for the winter..

Wrigers wrote:I think my worst case scenario has just been confirmed. After a few weeks of rough running and smoke from n0 1 cylinder, i thought it might have been a carb problem.
But oil coming out of the exhaust drain hole, oily plugs, and I think a valve seal has give up, more annoyingly on a rebuilt engine with 300 miles on the clock. The head was overhauled but not with Genuine Kawa seals, and I think this the problem.
What are people's thoughts???? Especially on the seal issue,,, has it ever happened to anyone else.
All the symptoms are there, excess smoke on start up, on idle, and under acceleration....
Another job for the winter..

Just taken the exhaust off n01 and the top of the valve looks very oily, picture not the best nut it gives some idea of what's happening.

Hi Wrigers
if an oil seal has given up after 300 miles I would contact the man who did the engine overhaul.
Or it was a bad quality oil seal or it was placed wrong. SH*T happens, sadly enough.
If you remove the head to replace the oil seal I would suggest you replace all of them, don't take any risk, use genuine Kawasaki oil seals or good quality Viton oil seals and make sure they're placed correctly.
Good luck anyway!
GrtZ
Philippe

Thanks Philippe, the head was done by a well respected builder on here, but to fare i sent him the seals that came with a gasket set, carnt remember what make they were.

As Phillipe says,the only seals worth using are gen or Viton,all the ones out of gasket sets give up in very short order!its is possible to replace seals without head removal,never done it myself but have seen vids using compressed air and coiled rope,know at least one respected member on here who has used the compressed air trick and he reckons it works ok!

Exactly how much smoke??
If its got an oily plug it would have to be the inlet valve seal on #1
If its a moderate amount of smoke i'd say valve stem seals but if its copious amounts more likely broken ring, score in bore, oil control assembly incorrectly set or as seems to be the case most often a ring up-side-down. Bleeding head gasket!
I ask about smoke because it will smoke way more with some ring / bore issues than if it had no valve stem seals at all.
Missing (or terminally damaged) valve stem seals will allow some oil through but damaged bore or up-side-down ring will pump it out.
Seen a great deal of both recently.

AL

Thanks A1, its always hard to describe smoking accurately, but its not chucking it out, i would describe it as moderate, more so on initial start up.
what i am thinking of doiñg is removing the barrells anyway whilst im doing the job, and just checking the ring's .

Agree how long's a piece of string?!!! If youre planning to take the head off anyway, i would suggest the barrels as well. You only want to do it once and whilst possible, you will be lucky to get the head off without oil coming across the face of the base gasket.
I have Vesra or Athena valve stem seals on mine on recommendation (came in the gasket set) and for a few thousand miles all in the redline this year it is perfect. Always used expensive APE Viton greenies before and had no problems with them either!!!
You didnt say what the reason for the re-build was! Was it an issue related to oil control? What was done in the re-build?

AL

The head was done as part of a full engine build. It was in poor condition and required new guides, all valves re cutting in etc.etc. The guy did good job really, these things happen, its just a pi..er after just 300m.

Just done a cold compression test on all 4 pots before I start anything and it's reading 105psi on all four, even with a drop of oil on top to see if anything's leaking. Is this reading ok , considering the engine was cold. Couldn't do a warm one as id removed the exhausts.

100 PSI is service limit,would guess 10% extra when hot on your cold readings,throttle fully open.

105PSI cold is acceptable and especially if your getting that on all four (as opposed to wildly varying readings).

Cheers chaps,,,,,,

For reference 105 PSI is 7.5:1 comp ratio.
Thats pretty low and starting / overall performance may well be affected.

AL

Not sure how it can be improved, it was redbored with new pistons and rings during the build.