
I was in a local garage getting my tin-top MOT'd a few weeks ago, when two bikers brought in their Kawasaki Z1300 bikes in for testing.
There are plenty of more modern bike engines around that would give far more power - but wouldn't it be something to have a straight six under
the bonnet!
The down-side became clear when I spoke to the owners - apparently it's getting very hard to find spares these days.
Would be impressive though! 
't see why it wouldn't - there's more than enough room ahead of an R1 engine, so a couple more cylinders should go OK.
It may be a bit short on power compared to modern units, but maybe a supercharger...
I remember seeing an article a few years ago where some guy had used two of these engines to build a V12
Which he then squeezed into a standard -looking Z1300....................
They were only about 120 bhp , but sooooooooooo much torque it felt like a lot more .
I worked as a mechanic at a Kawasaki dealers when they were a current model and once had to re-build one from a pile of bits after a camchain snapped
during a service 
Found it !
Now that would make a nice engine for a seven................
[Edited on 16/7/08 by clairetoo]
They're a big, heavy lump and now becoming quite rare. I would just keep this as an idea and go no further.... 
Purely a pipe-dream... 
Here's a bit of footage from the king of all stunt riders!
Click here. I thought he was dead, but apparently I'm wrong! 