Missing at low revs

[lb99]

My z200 misses just off idle, full throttle is fine (nice clean plug) idle is fine too, but it misses and farts at traffic speeds, and makes the plug go all black.
the float level is ok, and playing with the idle mixture just moves the miss around, and makes it harder to start, the hesitation is in the first quarter of the throttle and it makes it awkward to ride in traffic unless you keep it on the boil, where should I look to from here?

[frogfeaturesFZR]

When did it start ?
Anything new done to the bike ?

[rogson]

Most likely a problem with the needle.
It could either be worn (thirty-odd year old bike right?), or set too rich.
Either way try lowering the needle - i.e. put the clip one (or even two) groove(s) higher. If it's worn you still might not get it to lean out enough because the clearance between the needle and the jet (the tube it sits in) will be enlarged to the point that it can't adequately restrict/meter fuel flow. Only solution then is a new needle and ideally a new jet as well.

[lb99]

Most likely a problem with the needle.
It could either be worn (thirty-odd year old bike right?), or set too rich.
Either way try lowering the needle - i.e. put the clip one (or even two) groove(s) higher. If it's worn you still might not get it to lean out enough because the clearance between the needle and the jet (the tube it sits in) will be enlarged to the point that it can't adequately restrict/meter fuel flow. Only solution then is a new needle and ideally a new jet as well.

the needle is on the middle setting, I might lean it off a bit and see if that helps, its like it goes super rich just off idle(puts out a puff of black smoke when you crack the throttle.
good point about the needle wearing, its a keihin carb so parts should be ok to get, I was worried about it leaning out too much and heat seizing as I have to pretty much hold it at full throttle to keep up with the traffic on the way to work(100k+) for about 10km

[rogson]

At 3/4 to full throttle you are running primarily on the main jet. If you are worried about over-lean running at this point you should consider a bigger main jet (although you said the plug looked OK - not white for instance?).

[lb99]

the plug was a nice coffee colour after a couple of ks of full throttle then hit the kill switch, but any low speed running at all results in a black plug.

the ignition timing seems ok, and the advance works too, would the condenser cause this if it was faulty?

[Motu]

Bring it up the the problem revs and turn the fuel off,take the fuel line off if you have to.Let it run out of fuel - if the revs increase then it's definatly a rich mixture and you can continue finding out why.If it just dies then I'd be looking to an ignition problem.

[lb99]

Bring it up the the problem revs and turn the fuel off,take the fuel line off if you have to.Let it run out of fuel - if the revs increase then it's definatly a rich mixture and you can continue finding out why.If it just dies then I'd be looking to an ignition problem.

good idea, cheers.

should I be checking the float level with the engine running or not?

[T.W.R]

good idea, cheers.

should I be checking the float level with the engine running or not?

If you run the motor & switch the fuel off your going to get an increase in revs as the fuel deminishes as the float bowl emptys out.

To check the float level you have to remove the carb, invert it remove the float bowl retainer clip & measure the height of the float off the level edge of the carb body (the flat edge of the float chamber).

Check your ignition timing primarily, it sounds more as if the timing is retarded (particularly seeing your having to hold it full noise to do 100km/h), different models of the Z200 have different timing marks, early models have timing at 10 deg BTDC & later models 13 deg BTDC. Also check the timing advace weights aren't sticking.

[Motu]

The revs will rise a little just before it dies if the float level is correct - if the float level is far too high or the jets are too large then it will race as it leans out.

[paturoa]

The revs will rise a little just before it dies if the float level is correct - if the float level is far too high or the jets are too large then it will race as it leans out.

You've done this before havn't you.... like that technique I'll use it next time.

Does it work as well on a 4 cylinder too?

[lb99]

If you run the motor & switch the fuel off your going to get an increase in revs as the fuel deminishes as the float bowl emptys out.

To check the float level you have to remove the carb, invert it remove the float bowl retainer clip & measure the height of the float off the level edge of the carb body (the flat edge of the float chamber).

Check your ignition timing primarily, it sounds more as if the timing is retarded (particularly seeing your having to hold it full noise to do 100km/h), different models of the Z200 have different timing marks, early models have timing at 10 deg BTDC & later models 13 deg BTDC. Also check the timing advace weights aren't sticking.

ok, cool, the manual at the local library only tells you how to check the fuel level with the carb in place, using a plastic tube as a float gauge, the level should be 4-6mm from the gasket surface on the carb, do you know the correct float height. I dont have to hold it completely full noise to get it to do 100k, but its getting up there, you can get it up to 125-130km if you hold on for long enough, but only in the morning when the air is denser.

[lb99]

can anyone tell me where to get some keihin jets from?

the needle seems to be impossible to find

[T.W.R]

can anyone tell me where to get some keihin jets from?

the needle seems to be impossible to find

The Kawasaki parts listing quotes the following:

Carburettor # 16001-1028 /-1068 (Z200 models A1/A2)
Carburettor # 16001-1027 (Z200 models A1A/A2)

Needle # 16009-1005 , use for 16001-1028 /-1068
Needle # 16009-1025 , use for 16001-1027

Main Jet # 92063-1009 (#105) std in 16001-1028 /-1068
Main Jet # 92063-1114 (#110) std in 16001-1027
Main Jet # 92063-1008 (#100) race use only ( )
Main Jet # 92063-1118 (#115) race use only ( )
Main Jet # 92063-1011 (#120) race use only ( )

Pilot Jet # 92064-1002 (#38)

Those numbers are Kawasaki parts listing so if you quote those they should be able to supply them or at least source them.

Not sure on the float height setting sorry, something tells me it's close to 13mm +/- 2mm either way. I'll see if i can dig anything up.

[Motu]

Diagnose correctly before you start thowing parts at it,if you get it wrong you'll disguise the real problem and make it harder for yourself....or the poor bastard who has to sort it out for you.