actually, if you can clearly see a groove in the cylinder, someone may have o-ringed it. its made out of a copper o-ring. i noticed you zila is an 87 and is notorious for blowin head haskets, so it possible someone just o-ringed it.... you wil have to do some research on this one

 

When I took it a part some on cut a 88-90 head gasket to make it fit, I thought the groove he was talkin about was the sleeve meeting the cylinder but I thought that he would know best, he recond the metal ring sat on that so called groove. The old 8mm studs on my head were taken out and replaced and I used hardened steel bolts I think there 10mm. I mix 125ml of oil to about a gallon of petrol. Its not p!ssing out the coolant yet only a few drops, I suppose you have you'r ups and downs.

 

Very bad advice butters!
I'd suggest getting online and doing a search about jetting, and performing plug reads. LEARN the different jet functions, and how to adjust properly. All the info is out there... just look for it, read it, live by it... It's not that hard.
Merely dropping the main 3 sizes could be a recipe for disaster (Lean = kaboom!)
There's just too many variables to toss out advice on jetting.
Tinkering with jetting without at least SOME understanding of it will cause you nothing but headaches.

My $.02

 

Thanks, I haven't seen my zilla in a week I'm so busy studying for my junior cert examiniations (there state exams here in ireland) and over the weekend i had to finish my woodwork project, so much to do its killing me but its all over 20june. I can't even get to work on my poor zilla.