Z1OwnersClub GB

Can anybody recommend a reputable engineer in the Midlands to take a look at my crankshaft?

Posted last month under "alternator problem", when i turn my engine over by hand, there is a 0.13mm runout right at the very end of the taper on the crank. When measured on the starter gear bearing surface, the runout is 0.03mm.
Looks like the c
end of the crank may have been bent in a previous crash.

Can these things easily be straightened? When the rotor is fitted and the generator cover installed, the rotor seems to be interfering with the stator and not allowing the engine to turn over.

Thanks.

SEP, Castle Donington.
Regards
Steve

secondhand crank might be cheaper....

z1bman wrote:http://www.ebay.co.uk/itm/Kawasaki-Z1000-Z-1000-A-Series-Engine-Crankshaft-Crank-And-Rods-/351578925386?hash=item51dbbca94a:g:yegAAOSwEgVWR6UH

DK Spares

Which barn did they find this in

Crank may not be bent but just need trueing up.
If over revved (high speed missed gear etc ) the crank can twist on its pins ( to varying degrees depending on the speed and torque at which it occurs) which would lead to the symptoms (amongst others) which you describe.
With the rotor being heavy and with a large centrifugal mass the l/h end wed is more susceptible to being thrown out of plane which will cause the rotor to run out of true.
If you have some V blocks and a dial gauge it will be easy to check if this is the case once the crank is out of the motor.

Thanks for the tips guys. The newly rebuilt (but never run) engine i've bought came with a box of spares which includes a mashed up and welded generator cover which suggests the bike may have been crashed inspiring the project i have bought, part done.
I'll give SEP a call in the week.

you're right though Chrisu, may well be as easy to just get another one, they seem reasonably priced but may be buying something just as bad so would need measuring. Photos of the ones i've seen on fleabay seem to have the familiar damage on the taper which mine has.

ChrisB wrote:you're right though Chrisu, may well be as easy to just get another one, they seem reasonably priced but may be buying something just as bad so would need measuring. Photos of the ones i've seen on fleabay seem to have the familiar damage on the taper which mine has.

a bit of grinding paste on the rotor will sort that & use schnorr washers on the bolt to prevent it coming loose

Whip the crank out and send it to Chris Applebey. He'll have a spare web and I'd have it welded whilst it's out.

z1bman wrote:

ChrisB wrote:you're right though Chrisu, may well be as easy to just get another one, they seem reasonably priced but may be buying something just as bad so would need measuring. Photos of the ones i've seen on fleabay seem to have the familiar damage on the taper which mine has.

a bit of grinding paste on the rotor will sort that & use schnorr washers on the bolt to prevent it coming loose

^^^^ this

Update on the crank for anyone interested. SEP re pressed it ( or hit it with a big hammer!) had to wait 5 weeks but only charged me £50 which I think is reasonable. Just rebuilt the motor, runout now measures around 0,03mm which I can live with. Just need to swap out a couple of shims and it'll go back in the chassis for 'fingers crossed' time!