TOPIC:

Over the years I have stated if there is an electric start the kick starter is there only for emergencies. They are not meant to be used all the time. The mechanism  is weak and not meant for extended periods of time. Oh it will work for a while but there is no bushing inside to support constant use. It just fits into a raised hole in the aluminum case. If that breaks the engine is junk. My advice? Fix the starter. 
Steve

Yes Steve, you spoke my words.
Wisdom and knowledge is a privileg no money can buy!
It´s a lifetime learning process. It´s impossible to fill an limited/full brain.

Never had much use for electric start systems myself. I prefer the old school kickstarter. On the Kz900/1000 motors the electric starter system adds about 15 pounds to the weight of the bike. Less weight on any bike is free horsepower!!! Ever since I built my Kz1000 MK.II back in 1979 its been kickstart only. The load bearing area of the kickstart shaft rides in a bushing not on the case itself. The other end of the shaft that has very little load on when you use the kickstarter does ride on the case itself. I have NEVER had any type of problems with any part of the kickstart system on my Kz1000. And I run humongous amounts of compression in my motors. 230~245 of cranking pressure is the norm for me. Even the kickstart lever is the very same one I have used on all my motors since back in 1979. It still shows no bend in the arm yet. My motors always start within one to two kicks and I always engage the kickstart gears before I give it a kick. And never let it fly back after the motor starts. Kawasaki did a great job when they designed the kickstart 900/1000 motor and the kickstart system is just one part of that great design!!!! Don't know much about other Kawasaki four stroke motors of how good their kickstart systems are. If its a 900/1000 motor I say kick away!!!!

 

Kicking a 750 cc twin is more difficult as a 900/1000 four.
I have seen broken/sherd off kick starter shafts here!

A defect starter clutch can harm your engine and your health. Kick start an engine is an option but only if you repair or remove the starter clutch.

kzrider.com/forum/2-engine/143225-twin-7...utch-failures#149604

My KZ1000 build,(1327cc) motor, from back in the 80's, was kick start only, as the stock starter hardware  was not compatable with the newer crankshaft, and I did not want to go with a remote starter set up. It worked out fine once I got the hang of it. I do admit the kick lever is not the original, as I have bent more than one while putting my leg into it. I believe the ignition timing was somewhat advanced which made the lever 'kick back' even worse. If I could have electric start again ?  Yes I definitely I would prefer that. 
 

When I was running gasoline on my 650 drag bike I kicked it. 70 mm pistons at 220 PSI with the stock ignition advancer welded at 40 degrees advance. You just need to be aware of where the pistons are at (4 strokes) so you can kick it at the optimal time.

That bike got converted to alcohol and a magneto so the kicker got dumped, could not put back the stock starter motor which even at 24V would have been too weak to drive the crank. It currently uses a starter cart with two 1000CCA truck batteries hooked up at 24V, starter motor is out of a 440 Chrysler - This in some conditions barely turns it over.

New drag bike is 1327cc gasoline (200-210 PSI?) and I am going to kick start it using a spring loaded Dyna plate with a retard lever. Detent will be milled in the points cover, learned on the 650 that you don't want to kick fully advanced bikes without some kind of retard or compression release. I do have a CB900 starter in the wings and I know how to do a 24V button start setup. You need to melt the lead off the end of the rotor to get rid of that mass. No problem kick starting as I still do squats at the gym

New street bike build is 1197cc in a KZ650 frame, will have kicker and GPZ1100 starter.
 

@ injected.      Well said,  kicking at the optimal time was my getting the hang of it. Keep doing them squats and have a pair of stiff boots for the track. Good Luck to you.

As I said there is no bushing in the kick start. Not meant for every day use. Glad I still have mine. Saved my cookies many times over the years. 
Steve
 

Been kick starting my daily transport Z1R ( which has no starter motor fitted) nearly everyday for the 23 years since i built it.
That's 16,790 kicks at an average of twice a day so far.
The aluminium cover shows no wear where the shaft runs and the shaft is bushed at the ratchet gear end so extremely unlikely for any slop at the cover end to cause an issue.
The aluminium acts as a bushing material and all those motors running cams direct in the aluminium head would be in trouble if it didn't.
The cams would have far exceeded the 16790 half rotations of my kickshaft in the first few minutes of running.

While I'm glad our more seasoned members have had good luck with their kick start only bikes it doesn't counter the fact I've seen lots of broken kick starters over the years on street bikes. It maybe due to the owner is too lazy or cheap to buy a new battery, a bad charging system, a bad starter clutch or a dead starter  I thought it a mistake KHI removing it all together on the later bikes. When I saw the Z1R had the lever bolted under the seat I said to myself "Here it comes,"   Sure enough they removed it although they made the starter assy. harder to get to.   Instead of just pulling the starter or the clutch and rotor on the bigger fours the smaller ones are a lot more work to get to. Though I feel the KZ 750 twin motor is fugley I was happy to see the starter assy. is easy to get to. Kinda like my 350 Honda was.   As for the cams running in bare aluminum heads one oiling system problem can ruin a perfectly good head along with the lower end. That happened on my Honda but the cam rides in two end caps that are easily changed. Bare heads seem to be the standard with other makes and smaller Kaws. Planned obsolescence. 
en.wikipedia.org/wiki/Planned_obsolescence

I didn't know this when I bought my Z! but it being totally rebuildable has kept it on the road through today. 
Best investment I ever made. Like I said:
"The best of both worlds, speed, utility and vintage cool." 
 
Steve

I agree that kick starting a KZ750 Twin isnt as easy as other bikes, but my bike is properly tuned and starts on the first or second kick. If the bolts on the starter clutch arent backed out, I dont see the reason why it cant be kickstarted all the time. Also, having close to 10 bikes, I dont ride the KZ750 all that often. Maybe twice a month.