Z1OwnersClub GB

I have put one of my ST engines into Royston at REPS racing, he says the cylinder head has cracks running from the spark plug holes in No 2 & 3 to the exh valve seat, this is quite common and they seem to run well with no adverse effects, indeed these cracks look to have been there for a while.

Has anyone else heard or seen this on Z heads , any comments?
anyone got a spare ST head just in case ?

pretty common....and appear to have no serious issues unless you use the performance of the bike.

Yep, I've had 'em too & had 'em repaired, but I don't think they're too much to worry about & fairly common.

Ditto no worries...