Bucking KZ200

Greetings KZ enthusiasts,

New bike owner.
Have a clean '78 KZ200 with 6000 miles.

Starts well then a mile down the road she starts bucking like she's loses power intermittently. If I pull off the throttle she dies and I find that the battery is almost to completely drained.
The electrical (signals, etc) seems to follow suit with the trouble.
After a while I can usually kick it started.

The battery is new and charged.
Fuel flow is great through petcock. No gunk in the filter.
Spark plug is new.
The points appear fine to my novice eye.
There is no vacuum happening with the fuel as I ran it with the cap open with the same result.
No kink in the hose.

I've followed a few forum threads re: similar problems but nothing quite resonates with my specific troubles

Any thoughts would be appreciated.

Does it run fine when the battery is fully charged (up until it's dead again, of course)?

My first guess would be to run a diagnostic on the charging circuit (stator/alternator, rectifier, regulator, and associated wiring).

As voltage drops too low, coils can no longer produce consistant spark, and it causes the bucking/cylinder missfire you describe.

MFolks should be along shortly with a huge write-up on the how to...

Best of luck. I'll keep an eye on this thread...

sparkn wrote: Does it run fine when the battery is fully charged (up until it's dead again, of course)?

It does, yes.
The trouble really begins when I get up to highway speed.

TeK9iNe wrote: My first guess would be to run a diagnostic on the charging circuit (stator/alternator, rectifier, regulator, and associated wiring).

As voltage drops too low, coils can no longer produce consistant spark, and it causes the bucking/cylinder missfire you describe.

MFolks should be along shortly with a huge write-up on the how to...

Best of luck. I'll keep an eye on this thread...

Thanks for this. Will await MFolks.

Hello, vicarius, and WELCOME to KZr!

Perhaps the new battery isn't holding a charge.

With a fully charged battery, and no charging components whatever (i.e., running a total loss electrical system), the engine should perform normally for substantially longer than indicated in the reported history.

Would remove battery from bike;
Assure fluid levels are correct;
Charge battery fully;
Have battery load-tested.

Good Fortune!

Assuming the battery checks out ok, sounds like checking the electrical system is a good starting point. The Kawasaki factory service manuals give good instructions on how to check all the components plus a ton of other useful information. If you don't have one you may want to check out the ones listed in the link to find one that matches your bike's year and exact model. Don't waste you time and $ on a Haynes or Clymer manual. Ed

shop.ebay.com/i.html?_nkw=manual+%28%22k...=p3286.c0.m270.l1313

I think this is still a good link to a FSM pdf download. It might be bit slow, that will give you some time to round up some tools and a couple of brews.
home.comcast.net/~loudgpz/KawKZ200Man.pdf

650ed wrote: Assuming the battery checks out ok, sounds like checking the electrical system is a good starting point. The Kawasaki factory service manuals give good instructions on how to check all the components plus a ton of other useful information. If you don't have one you may want to check out the ones listed in the link to find one that matches your bike's year and exact model. Don't waste you time and $ on a Haynes or Clymer manual. Ed

shop.ebay.com/i.html?_nkw=manual+%28%22k...=p3286.c0.m270.l1313

Thanks for the link. I'll follow it now.

Guys,

A general thanks for all of your input. I appreciate it.

Since my last post:

I took back my new battery as the charge it held was weaker than my old one.

Went to start it, which has never normally been a problem. It ran for a second or two then died.
Tried it again. Same thing only this time it barked.
I say barked because I honestly thought it was my dog who was with me at the time.
Tried it again. It would turn but wouldn't fire.

Left it for awhile, tried again...same bark and died.
It hasn't started since.


I just pieced together a binder with a service manual (thanks to Motor Head) and parts glossary.
Was hoping to get some experience gradually...
Wasn't planning on troubleshooting in this depth off the bat.

Any thoughts? Perhaps this latest development is a audible clue leading to my original trouble?

My bike looks good sitting in the garage. I'll always have that, I guess.

"Bark" might have been backfire through carb, which may occur due to various causes such as leaking intake valve for whatever reason (insufficient clearance, etc.) or incorrect ignition timing.

If not already done, would assure valve clearances being within specs, and then perform compression test.

Good Fortune!

Edit