PLEASE HELP NO SPEED :(

at20 wrote:

hey i did what you said about test to see if im firing from both cylinders and and you were right one size instantly sizzled and disappeared but the other just sat there . now i gotta find out whats going on

Whats going on is that the sync between the two carb slides is too far off.

Remove the carbs and perform a proper bench sync as per manual.

Use a piece of hard steel wire (like thin welding rod) and set both the slides to its height.

When you hold the carbs up to a light, you should see nearly exactly the same amount of light shining thru the carb bodies as you open the slides together.

GL.

Could also be weak or no spark or grossly out of adjustment valves. There are worse possibilities, but we can ignore them until all the usual suspects have been eliminated. I bet the shop manual has a good diagnosis routine for a cylinder that is not firing.

I'm amazed that your KZ400 twin was able to go 55 - 60 mph with only 1 cylinder firing. Ed

650ed wrote:

I'm amazed that your KZ400 twin was able to go 55 - 60 mph with only 1 cylinder firing. Ed

+1

i checked my pjugs again today and they both look the same like its running normal i used the pic in my manual to compare plugs and they match with normal. so im starting to think it might be something else i cleaned the carbs as my manual told me to do it

i know im shocked too. im new at owning a bike so im trying to work on things myself. i just like how everyone here is willing to help

Are you 100% certain that all the tiny passageways in the carbs are spotless? Did you carefully blow them out with compressed air and poke them with mono-filament fishing line or copper wire?

Are all the mixture screws set according to the manual?

Were float heights and function checked?

Did you double check for air leaks around the intake manifolds? Are the manifolds cracked?

Did you synchronize the carbs when they went back on?

If these are cv carbs, did you check the diaphragms for cracks, tears or tiny holes?

Are the vacuum hoses in good condition and hooked up properly?

I know this seems like a lot of elementary questions, but when it comes to carbs, details are crucial.


Have you checked for good spark at each plug?

As long as you have the plugs out, a compression test would be a good lick.

Sorting out an old machine requires a great deal of patience, but fortunately KZs are pretty simple, so most folks can learn to do it with a minimum of expensive tools.

i cleaned everything so it was all spotless but i didnt adjust the mixture cuz i was afraid i would make it worse instead of helping. when i put them back on it ran alot smooth and i felt more power on take offs and idles. my diaphams were in good shap for something so old. i didnt have any hoses cracked or anything

i did a lil test run after my tune up and i noticed that the exhaust from the block on the right is a orang/brown tint from the heat and the onw on the left is still right chrome like is not even trying to get hot

If they are original Kawasaki pipes they should stay bright chrome unless at some point a cylinder was running very hot or someone polished the chrome off or it rusted off. My pipes are original and have no signs of darkening due to heat. The spark plugs (or a laser thermometer) are a better heat indicator. If it is idling smoothly both cylinders are firing. Here's an easy test: simply remove the spark plug wire from the spark plug on the cylinder you think is not firing and see if it will start and idle the same as it has been doing. Let us know what you find. Ed

ok ill try that and let you know in the morning

i took off the spark plgu wire that i thought wasnt firing to see if it runs different and it doesnt start right away but it will start and it still idles the same . i tried checking the timing and im still lined up with the (F) on the plate. i cant get the actual lines to match cuz the manual said some need to be lined with the edge of the (F) so i left it the way it is