KZ 650 / 750 opinion

Hey guys, just trying to get some feedback here. I've had a '77 KZ 650 for a few seasons now, and I've been wanting to fix it up a little. Recently I picked up a 750 LTD as a parts bike, but haven't really figured out what all I want to use. Originally it was for rims and misc peices, but now I keep looking at the double front discs and rear disc and then start thinking of swapping out just about everything.
What do you guys think? Should I start swapping parts and get a Frankenstein, or just stick with factory stuff?
Work and downtime don't intimidate me in the least, I just want something that's a little better than what I got now that I can call my own... I can post pics if you guys want.

pics always get people interested

imo,,,the 650 and 750 swap fairly well.....easy ect

Need pics to see what you're starting with. If the 650 is a nice original I wouldn't change it, but if it's already modified beyond redemption I'd consider making the changes. Ed

Sorry it took so long for the pics. Neither bike is pretty, but I really wanted disc brakes and mag wheels on the 650, so I thought this would be pretty straight forward and simple. As a bonus, I was really hoping for it not to look obviously non-stock.

Parts Bike


Daily Driver

If you are looking for opinions, I'd be glad to give you mine.

I'd say that customizing and upgrading is fine on old bikes, as long as you dont cut or chop anything, and dont throw any parts away. Make sure everything you do can be reversed. Many people have made the mistake of chopping up their old Z1's and KZ's, dump a lot of money into custom parts, just to later realize when they try to sell it, that the value of their bike has decreased by more than half.

The early 650/750's have identical frames. The disk brake swingarm should be a direct swap as with every other part. What year 750 do you have?

I have a 79 650SR with an 81 750 engine in it, slots right in no problem at all, forks/swingarm etc will all swap over with no issues as well.

Anytime I build a special, I make notes of which parts are from which year/model donor as after a few years you may forget and it can be a bit frustrating when ordering parts in the future

Anything can be made to fit, it just depends on how bad you want / need it.
None of the main parts (ignition & charging components, brakes, wheels, etc) from that 750 are going to be a direct swap to your 650. Some form or another of modification will need to be made. The 750 engine will fit your frame, but you'll need to swap in the afor mentioned ignition and charging components.

The '77 650 had a completely different charging system than the '78~ 650's did, as well as having a seperate regulator and rectifier. All of the 750-4 models are from 198*~, and ran electronic ignition (pulsar coil as opposed to points & condensers).

Swapping the rear swingarm to use the rear disc brake set up will require changing from brass swingarm pivot bushings to needle bearings (MUCH better IMHO), and you will need to find a method of attaching the rear master cylinder to the frame (easy to fab a bracket up).

Like I said, it's do-able. Just don't expect a direct swap on the major parts.

RetroRiceRocketRider wrote:

Anything can be made to fit, it just depends on how bad you want / need it.
None of the main parts (ignition & charging components, brakes, wheels, etc) from that 750 are going to be a direct swap to your 650. Some form or another of modification will need to be made. The 750 engine will fit your frame, but you'll need to swap in the afor mentioned ignition and charging components.

The '77 650 had a completely different charging system than the '78~ 650's did, as well as having a seperate regulator and rectifier. All of the 750-4 models are from 198*~, and ran electronic ignition (pulsar coil as opposed to points & condensers).

Swapping the rear swingarm to use the rear disc brake set up will require changing from brass swingarm pivot bushings to needle bearings (MUCH better IMHO), and you will need to find a method of attaching the rear master cylinder to the frame (easy to fab a bracket up).

Like I said, it's do-able. Just don't expect a direct swap on the major parts.

The charging systems are totally different as stated. As far as parts fitting the frame you should be good.

The 750 swingarm is already bearinged instead of bushed like the 77 650, so it will be a direct swap once you fab a bracket for the master cylinder

Wow.. there's a whole lot of info here, fair to say I'm pretty impressed
Kawickrice - the 750 is an 82 I believe, picked it up for 150 on craigslist a little while ago. It's almost complete, just missing a part here and there. I'm hoping the engine is good on it though...

Glad to hear of all the swappable items, now I'm thinking of some ways to put it all together and to get the good stuff working for me. I was hoping to be able to swap out the ignition, stator, and starter, I think all three are suspect on the 650, but it's not looking like that will happen anytime soon. I had to cup my hands over the turn signals when I took my license test because they were so dim, and the testing officer was polite enough to remind me they had to be visible from 300 feet, but since he didn't have a 300 foot tape measure, he let me take it anyway. Oh well, guess I'll just be buying new parts eventually.
One thing that I haven't really thought of is if the chain and sprockets were swappable, and if not, which would be better to use?