KZ750 in a KZ650 Chassis

Any Help or advise as I go into this project , Bike is a 1977 KZ650 but has a 1982 KZ750 in it ,, No wires hooked yet,, Bought this off ebay a day or so ago , Lots of extras came along with it including the bad 650 engine ,, The idea sounds good BUT ! One is on a standard points system as where the 750 uses stock electonic igntion ,, My Thoughts are use and after market electronic ignition in the 750 , with the wiring harness from the 650 ,, Or will the harness out of the 750 fit in there .. I have built bikes before with less BUT all helpful adivse useful Thanks and great forum Shoe

Personally I would keep the 750 harness with the 750 motor, if all the other electrics (reg/rec, handlebar switches etc) are 750. Else the aftermarket ignition with 650 harness, so all other parts plug in nicely. I saw a 650 with 750 motor and Z1R bodywork at local shop once. Sweet ride. If you get a chance 650 swingarm is weak point. KZ's not known for strong swingarms (old round tube technology). Nothing longer just heftier. Best of luck and have oodles of fun.

i am doing almost the same thing . i have a '78 650 and am putting in an '80 750 engine for this year (until i get my 1000 done that is)

i am going to fab my own wiring to fit the 650. but then i already have electronic ignition. but as for the rest i am going to make my own wiring from my 650 work on the 750.

let me know what kind of problems you run into!!!

good luck

The only difference between the two (engine releted wiring) is the alternator and electronic ignition wiring. You can use the 650 rotor and stator on the 750 and then it plugs right back in to the bike wiring, and for the 650 that already has electronic ignition, that one should be "plug and play". For the 650 that don't have electronic ignition, the simple answer is to use the points set up off the 650, or use the ignitor off the 750 and cut the ignitor plug off the 750 wiring harness and splice it into the 650 harness, then it becomes "plug and play".
My nephew and I stuck a GPz750 motor in his 79 KZ650SR, and I have a KZ750 motor just waiting for a KZ650SR to become available at a price I can afford (real cheap)

Can anyone tell me what the rear swing are weakness is ? It really looks heavy enough ..?? Thanks for all the info YOU ALL are very helpful ,, Shoe

better shocks will help with stock swingarm but they still twist really easy if you want to keep it cheap go with a 1000 kaw swingarm that way you can also convert to rear disc brake if you dont allready have one!goodluck,happy wrenching!

You can easily drag the footpegs with the stock swingarm. Don't worry about it unless your going to be riding very agressively at very high speeds.

The stock chassis starts to get a little out of wack at only triple digit speeds and serious lean angles. Even then as long as your smooth with your inputs it does pretty well.

I think I started something

I have a 77 650 with a 80 750 in also. My wiring on both bikes was hacked but I used the alternator from the 750 and the elec ignition from the 750 also. I pretty much combined to harnesses to make one good one. Does the 77 frame have disc or drum brakes, that is another hurdle to cross if you want the discs, or at least on my 77 650B model it was. Its not much of a hurdle though if you have a welder (I dont)

Click on my blue bike on the bottom for more details.

You will also want to use a regulator/rectifier combination unit. Your 77 has or had 2 seperate peices. 77 was the last year for the seperate units. You will have something that looks like this under your left side cover if you have the seperate peices. That is the regulator. The rectifier is under the battery box.

This is all very helpful and your pics the best ,, I bought both bikes off Ebay for 135.00 drove to Michigan last Sunday to pick it all up .. Not Sure What Bike I have kind of New to the KZ ,, It has Mag Wheels with Dics brakes , twin up front ,Larger Front fork tubes, It is in your Silver color . The 82 is a LTD so that is the engine I will use , I do have the old engine , not much good anymore since it was stored outside .. The wiring from the 650 has been cut at the handlebar switch But I have the peices parts to solder it back together ,, The 650 harness is in a box as the 750 harness is still on the bike , From your pics and looking the 750 over it looks like the harness is a swap over ? Maybe not though , I like how you took the bike down to repaint it all the work it back together , This is how I have done my bikes in the past with excelent results ,I want to keep the older 77 bike look as I just like it , The bike has Chrome guage covers , I will use an after Market front fender that didnt work out for another project , I will say my garage is pick up better than yours ? ,,well not really and its a good thing to coin Martha . I am really looking forward to starting on this project , But have a 550A to do first ..I want to say that this is the best web site I have ever been on ,, You Guys are great and not afraid to share your experience or Knowledge .. Dave ( Shoe )

Do you have any pics of the bikes yet? How about the auction number (inquiring minds want to know what you got) Sounds like a great deal regardless of what they are.

Item number 46021223930 Tell me what ya think of this and be honest please ..(: Shoe;)