Well last week i bit the bullet and put the ute on a trailer and took it to the tuner/shop to get the job finished off. Now i hadnt had the engine running long enough to really see if there was a problem, which there is....
I knew there was a nasty clunk in the bottom end which is half the reason i took it to the shop, but on further diagnosis they tell me that its not running on cylinder number 4 for some reason. The dizzy is firing the right shots etc. and theres compression in the cylinder but just not firing.
What could this clunk be anyone? And why would it prevent that cylinder from firing?

Ive whipped the head off and the piston isnt cracked, the bores are smooth but theres a fair bit amount of carbon residue on the piston crown...

I didnt touch the bottom end when i took it out of the sunny, just had to fit the new cam and that was it, the thing didnt have a clunk before hand so i duno what could have happened

Any commments welcome.

Cheers
Dave