Z1OwnersClub GB

Posted: **Mon Dec 18, 2006 6:38 pm**

What is the criteria for welding a crankshaft?
A friendly guy (mistakenly, thought I knew a lot about Z's) asked me the above question.

He told me he had a 1070 bore, high compression pistons, reasonably hot cams and smooth-bore carbs (I think he said 33mm, not the usual 29mm). He 's not into drag-racing, however he likes a quick reliable machine.

Any comments?
Regardz & have a happy ChristmaZ

Posted: **Mon Dec 18, 2006 6:44 pm**

Steve at Debben is the man for this, but from my own experience, a crank is very unlikely to twist under road use no matter how quick you ride. If the engine is in bits then personally I'd weld it, but I wouldn't do a strip down just for that purpose.

Posted: **Mon Dec 18, 2006 11:37 pm**

Most Z1/z900 cranks seem to be able to take significant punishment - although I've always tended to get mine welded when going with big-bore kit and cams - it's probably overkill for most smaller cc street motors.

The same is not true for the first year KZ1000 J motors - these are very susceptible to twisting - even with stock pistons.

Z1OwnersClub GB

Welded crankshaft ~ z1 series