1000 in 750 frame?

Just out of couriosity, will a KZ1000-4 fit into a KZ750-4 frame? The KZ750 frame is an H3. And are any parts interchangable between the two engines? Thanks!

Physically the 1000 will fit the space but it's not a bolt-in affair. You'll need to modify/make new engine mounts.

Later, Doug

...and most likely have to remove engine to adjust valves. Here is a 900 in a 650 frame. Same basic thing...

What mods to the mounts would be necessary? Could the mounting bosses on the frame be retained (it appears that just the mounting plates in Bluemeanie's pic were changed), and would moving the coils to a different spot help? Further, is the 900 a good engine, and would it be easier to fit the 750 frame? Just considering ideas.

The 900 and 1000(pre-1980) are physically the same exact size so you won't be making it any easier.

Why are you wanting to put a 900/1000 engine in your frame?

Later, Doug

The 900/1000cc engines are differnt from the 650 and 750's The 900 was first to production. It has a pressed together crankshaft with roller main bearings and one piece rods. The 900 has a dual point mechaical ignition. The 650 was developed from the 900, and improved and simplified design the 650 has a conventional single piece crank shaft with bearing inserts (like a modern car engine) with conventional connecting rods. The 750 is a remake of the 650 with a larger bore. Most 750's have an updated cam chain design and I believe all had solid state ignition. The 750 would also run a more reliable constant vacuum type carburator.

The bigger motor makes more power and has tons of aftermarket parts availalbe, the 750 is lighter and a bit simpler mechanically. Realistically in stock form there is about 15 HP difference between the two. But the sky is the limit when you start modifying them. The 900 is overal a good engine, but it has a few deamons, the 650 is considered one of the best japanese motorcycles ever in terms of reliability.

Again why do you want to put the bigger engine in?

put an 810 kit in the 750 and some GPZ cams uless you come up on a modified 900 or 1000 you win