more 650 engine swap questions

ok... I have a 1978 kz650 and I just found a deal on a local 1980 kz750 4 and I'm wondering if the engine fits in my frame... I believe the lower ends are the same? just the head and jugs are different? will my 650 exhaust fit the 750 engine? and the electrical... I have a dyna s and accell coils on the 650 now will that stuff fit the 750 as well? can I use the stator and rectifier from the 650 on the 750? and is there a way to use my kickstarter from my 650 on the 750 or is it not worth the trouble? if I understand correctly there's 10 more hp in the 750... and I'm planning on the 810 kit later on down the road so this is something I really want to do. any help is appreciated. thanks.

yes it will fit.
yes the exhaust will fit.
you should be able to use the dyna on the 750.
You should use the stator and rectifier from the 750.
Adding the kick start would be a big pain in the ass.

We put a GPz 750 in my Kz650Sr frame and we used the 650 stator/rotor to make the charging system plug.n.play. Just the downfall of using a GPz bottom end is the Off Set sprockets are getting harder and harder and harder and harder to find :laugh::laugh: . Steell found and purchased them for me. On the motor mounts we found some bigger gaps so we used alotta washers has spacers temporarily until I made some. Didn't have to drill any holes out bigger ether to mount the motor

so are the CV carbs that come on it any good? or would the VM carbs off my 650 be better for performance?

You could put the 750 top end on your 650 bottom end, that would keep the kickstarter

Of the two sets of carbs you listed, the CV34's would be best, BS34's would be better, but EFI would be best

Warning:

I think tuning EFI is a lot simpler than tuning carbs, and does a much better job, others think carbs are better. We argue about it sometimes (Where did the devil emoticon go?)

any other benefits to putting the 750 top on the 650 lower than just the kickstarter? aren't the lowers the same except the 5th gear ratio? and the kickstarter of course lol...

Why not swap everything from the 750's crankcase upwards. You will go from 652 cc's to 738 cc's using the 750's pistons, rings, cylinders, idler gears, cam chain adjuster and cylinder head. You can use the same roller cam chain and won't have to worry about electrical or sprocket mismatching. The swap shouldn't take more than an afternoon if you have a buddy helping out and the 650's bottom end won't have to come out of the frame. Exhaust is identical between the two bikes.

As far as the carbs go, might as well use the ones that came on the 750 if they are in decent shape.

Cheers-Colin Firth-Ontario Canada
1977 650/810 big bore. Wired George Mikuni 29 Smoothbores, Gpz 750 goodies tucked into a milled, ported and polished 650 head. Looks stock with the factory Moondust Silver paint job, but it don't run like a stocker when

gives me something to think about... but is there any benefit to the 650 bottom end over the 750 bottom end other than the kickstarter? I mean the 750 is a newer engine w lower miles than my 650...

The only benefit of the 650 bottom end over the 750 is the kickstarter.