There is a 29 horse kawasaki Hyper that I am looking at and wondering if the Kawa's are any good for mudmotors.

there has to be lots of used Briggs motors out there for sale with this economy,I'd look that route if you can find a good 35hp motor, price should be close to the kawa

They're very nice lil' motors, but there were a couple of issues i had with mine:
* hit a log while hunting = busted fan & radiator
* electrical system trouble = new harness, ECU, & sensors (very expensive if you don't have any warranty)
* stock mufflers wouldn't hold up (no surprise there)

I think you'd be better off going with an air cooled engine!
I wouldn't suggest buying a used on either (they are very expensive to repair when compared to an air cooled engine)

Parts are considerably more spendy...example: fuel pump. Motors don't seem to have as much torque under load as an equivalent HP Vanguard motor.

The EFI is nice.

Had a 29 Kawi and have run Vanguard ever since.