KZ won't idle and surges on throttle

This Kaw is about to be rolled into the ditch for the city to dispose of.

1984 KZ700a1. This thing road pretty good when I last rode six-years ago. Started up easy and had power. I haven't messed with anything between then and now.

So, since it sat, I cleaned the carbs. Gave them a long bath and blew 120psi through every last opening. I can blow freely through each with my own breath and I know where the channels lead so I can tell there is a strong stream coming out the other end. And if it's not strong, they're at least even between each carb.

I've done this six-times now and I still have this problem!

When I try to start it, it won't start with the pilot screws any less than 4 whole turns out! If I turn them in any degree, I need the choke to start, but once it does start it surges to 7,000rpm and will not come down! Half choke, full choke and everything in-between, it either dies or surges.

When I can get it to sit around 1,000rpm by finessing the idle adjust and mixtures, I hear a very distinct knock in one or two cylinders. Hard knocks that shake the concrete beneath me.

I'm using all stock parts.
The diaphragms have NO microscopic holes and they're seated correctly in the grooves.
The slides move up and snap back down freely, no resistance.
I've sprayed all of the boots on both sides of each carb with a heaping dose of WD40 to find a vacuum leak, nope!
The ports on the top are plugged or going to the recirculator regulator thing.
Needles are set to second from top groove.
The floats are all equal and are not over-filling. I set them according to the KZ manual. About 3-4mm below top of bowl.
Cam chain tension was set.
Valve clearance was checked cold.
Cam timing is spot on.

Please save this thing from the heap. Either I'll fall in love with it if it works out, or I'll have zero hard feelings watching it flip over in a ditch.

Using the choke to start a cold KZ engine is normal. What are you using for air filtration? Ed

I know that some bikes need choke, but no matter what I do, using choke causes it to surge straight to 6-7k. If I push it in a little it just knocks and dies.

I'm getting a pop from the carbs now and then too. When I pull them off, the boots going into the engine are soaked with fuel!

I'm using the stock setup with a newly purchased air-filter, since my last one disintegrated when I removed it. All boots are snug and again I checked for vacuum leaks.

Thanks.

I know you don't want to hear this but if it ran good when you parked it and now it doesn't it is going to be your carbs. Did you happen to store it for 6 years with gas still in the carbs and tank? If you did then they are still clogged, I know you said you cleaned them a lot but you missed something.

Everything was thoroughly drained and let evaporate for the day. No chance of the crap turning into varnish. I never let fuel sit in it before and at no time did it sit for more than a day without getting some highway time.

What could it be that's causing such an issue?

For reference, if not already done --





Would also assure that the timing advancer is properly functioning, and not sticking or hanging due to rust or corrosion.

Good Fortune!

If needed, references from KZr's FILEBASE --

www.kzrider.com/filebase/doc_download/50...retorrebuildtutorial

www.kzrider.com/filebase/doc_download/45...an-a-repair-tutorial

Good Fortune!

OK I've blown through the carbs several times and the channels are clearly free of obstructions.

Where is the advance on this thing? It's an 83 and uses a CDI. I don't see anything around the spark unit that seems to be like an advance...

FootDragger wrote: ...1984 KZ700a1....

FootDragger wrote: ...It's an 83 and uses a CDI. I don't see anything around the spark unit that seems to be like an advance...

At some point in the various model lines, Kawasaki replaced the manual timing advancer with an electronic timing advancer.

I don't know which advancer is fitted to the bike at hand. One way to tell would be to remove the point cover and look through the timing window to see whether or not there's a manual timing advancer.

Good Fortune!

If a vacuum operated petcock is fitted, would assure that it's not allowing gasoline to run down the vacuum hose.

Easy enough to rule out such possible issue -- cap/plug the vac nipple at the carb that usually supplies vacuum to the petcock. Then test run with the petcock in Prime position.

Good Fortune!

Running with a gravity remote tank and all of the vacuum lines are plugged.

It seems there is no advancer here at all! I was really hoping that that was the issue, now I'm boned.

Check valve clearances and cam timing as well. Crap. Looks like it's off to a dishonorable grave, ole bird.

Not sure if this applies to your bike, but does it have a fast-idle screw? If so, then check out Loudhvx's write-up about fast-idle problems here:

Loudhvx Fast-idle modification

When I read the first sentence on his write-up, it sounded like the same problem that you described.

Hope that helps...