No power above 6000rpm

Jrbrownie00 wrote: Plugs are b8es. Non resistor version as the manual says

To reduce the soot building up on the plugs you may want to try switching to B7ES plugs. The Kawasaki.com parts diagram show them or the B8ES plugs to be acceptable, but the B7ES plugs are 1 heat range hotter and may reduce the soot. Ed

Patton wrote: Old hard cracked plug wires may leak voltage.
And sometimes old resistor style plug caps may provide too much resistance.
Old ignition coil(s) might possibly have developed an internal short at higher rpms.

The Kawasaki dealership likely has an ignition coil electrotester that determines strength of the furnished spark under load at high rpm.

Good Fortune!

I tried brand new dynatech solid core wires with Non resistor caps and had no luck either. Switched back to stock as I figured maybe they were part of the problem. Coils definitely look original though.

650ed wrote:

Jrbrownie00 wrote: Plugs are b8es. Non resistor version as the manual says

To reduce the soot building up on the plugs you may want to try switching to B7ES plugs. The Kawasaki.com parts diagram show them or the B8ES plugs to be acceptable, but the B7ES plugs are 1 heat range hotter and may reduce the soot. Ed

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That's worth a shot, for the $10 bucks it'll cost. Good idea

Have you checked the voltage getting to the coils, primary side?
Does it act the same, at different throttle openings? Will it rev past 6K at 1/2 throttle?

Is there any doubt about battery condition, holding a full charge, etc?

And given perfect battery, as Motor Head mentions, its full voltage should be getting to the coil primary terminals.

Good Fortune!

One thing I haven't done yet because I don't have a volt meter is check voltage at any point in the circuit. The battery was purchased from a local parts store the week I bought the bike so it's only 4 months old. It seems to hold a charge fine but It has died on me a few times back before I replace the starter clutch and it took forever to catch, killing the battery.

I don't have a problem spending money and replacing something I I know it will fix a problem but I don't want to bug things just on a guess, ya know?

I appreciate the responses so far... I have the manual but it can be tough to interpret if you don't know exactly what your looking for.

Ignition coils are multipliers, voltage in, voltage out. So if IN is low, then out is also.
Also if you had a charging issue, coil voltage will be low. The also if you have excess AC Voltage, from a leaking diode in the rectifier, you may have an Ignitior acting up.
But what does it go at different throttle settings? Possibly to rich on main jet, if 3/4 and above.

Motor Head wrote: Ignition coils are multipliers, voltage in, voltage out. So if IN is low, then out is also.
Also if you had a charging issue, coil voltage will be low. The also if you have excess AC Voltage, from a leaking diode in the rectifier, you may have an Ignitior acting up.
But what does it go at different throttle settings? Possibly to rich on main jet, if 3/4 and above.

I'm not sure I fully understand your question but I can go full throttle up to 6000ish Rpm and the bike pulls hard and feels normal. Its tough to ssy what it should feel like because i bought it and it needed wuite a but if work and cleaning. I'm going to take a run to harbor freight in the and buy a cheap multimeter. I'll report back

Cv style carbs will only open the slide up completely when engine demands. So what your thinking is WOT, may not be. It may be that at 6K they finally lift. So keep that in mind when trying to jet. Also are you sure the carbs are working properly, slides are sealed on the lids, no holes in diaphragms, nothing blocking the vents in the bellmouth/ airhorn from Pod's?
Also an engine is a air pump first, so nothing restricted in the EX? Air filters?
A compression test will help verify engine condition, and Valve timing.

What manual is being used? Hopefully an official Kawasaki Factory Service manual.

Free online downloads of the FSM are available if needed.

For reference if needed, may use this link to wiring diagram in KZr FILEBASE:
Click > www.kzrider.com/filebase/doc_download/310-z750h3


Generic example --



Good Fortune!

6000 rpm does sound like the transition point from the needle to the main jet.
Get something a little better than their give-away meter.
Sears has some pretty decent ones for less than $20.

Patton thanks for that diagram, great reference. I'm going to try some of this stuff today, I'll drop a line later on and report my results. I know it could end up being something really simple.