What do you guys think...should I go for it?

Mike,

Those early Ninjas had transmission and valve seat issues and sometimes rods.

The cams rode in the aluminum head, there were NO bearings. So whatever he means by spun intakes sounds like a junked cylinderhead to me.

Valve seats chipped badly. Valve faces were junk. You could tie up a pile of money in a cylinderhead in a heartbeat

Also, if you get it, there are 2 different size head bolts for them. Early had 10mm and part way through production it went to 11mm. So parts may not swap from motor to motor quite so easily. The bolts go through the head & block and thread into the cases.

You could pull the threads out of 11mm cases by trying to torque up 10mm bolts by mistake.

3rd & 4th gear on the output shaft sat back to back with a washer and circlip on each end of the pair. From banging gears hard, the washers would get concave shaped. Then all of a sudden BLAM.....2 gears engaged at once....helluva mess;)

Rods on #3 cylinder could be a problem.

Setup properly those were running little SOB's. Unfortunately they were the first generation of Kawasaki throw away motors....

I built several of those engines during the late 80's for a guy that was drag racing. They're low 10 second bikes with all stock parts if you set them up correctly.

Anyway.....thought I'd give you a heads up.

then of course there is that. personally though i really enjoy this bike and know quite a few people that are right into them and have ridden them for years so it's a pickum i know what i would do myself but i can't every let a wayward motorcycle go.