750 engine swap

Hello members,new to kz's,I own a 90 zephy 550r and a 84 gpz750..My new gpz 750 has no compression,bought from a guy who tried to freshen up the engine and failed,timing is on,but readings are nill to low.Question-im currently a low buck guy,but I would like to ride this gpz,I love the style and feel of it,slightly customized.Will any other engine drop in,thats not a gpz,and function with my 84 era electrics,see alot of 2000-2002 zr7 engines for 400. or so.i will rebuild the old one at my leisure.Any input is appreciated,looked on the net already,cant find any solid info.thanks

The timing of "what" is on?
First thing I think if after a fresh rebuild with low compression is the builder built it with the camshaft timing way off or screwed up the shim clearances and you now have bent valves or if lucky, you have valves being held open.
If that's the case pull the head and check it out before wasting time and money on engine swaps.

KZ 650 or 750 (4 cylinder) can be bolted in. Get the airbox too so you can use that too. Voltage regulater for the alternator too. There are 3 types.

From the the first topic linked below, the ZR7 engine swap to a 650/750 is the same as doing a GPz swap, so I would think the ZR7 & GPz engines would be the same as each other, fitment-wise.
KZR topic --- zr7 motor in KZ750 by turboguzzi

Another topic I've saved. w lots of good photos
KZR --- GPZ750/810 racer running by turboguzzi

edit: fixed the links. doh.

Your links are the same.

The first should be.
kzrider.com/forum/2-engine/602366-zr7-mo...n-kz750?limitstart=0

Thanks. I just now fixed them. both were messed up. doh. the second one now begins on page 1.

An early if not all 650 motor's will not be a bolt in the mount's on the case are wider
the GPz is a rubber mount motor and has narrower case mount's.

I bolted an '82 750GPz engine into a '77 KZ650 frame. No mods needed. They changed the frame for the GPz rubbermounts.

He's asking about a ZR7 (ZR750) engine for a ZX750 GPz.