Bought a used 2007 Kawasaki Eliminator BN125A7F
USA NOT California
Carb Mikuni BS28
Had 423 Miles, now 1050.
Had been in storage for 5 years.

Was running very lean.
Hanging idle.
Exhaust pipe is turning dark.
Plug insulator was white...you'd be ecstatic if your
teeth were that white.

I drained the fuel tank and carb. Was pristine...no gunk at all.
I added a fuel filter. After 600 miles, it's clean, no gunk at all.

Seafoam and major adjustment of the pilot screw
fixed the hanging idle.
I put one range colder spark plug in it.

Was detonating in almost every throttle range
on acceleration.
Valve adjustment is right in the middle of the spec range.
Air cleaner is clean and oiled.
I've been all over it with propane looking for air leaks.
Only thing that raised the idle was shooting propane
into the air box.

I've found very little on the web related to this bike.
What little there is is heavily weighted toward,
"It's running too rich," but not much in the way
of solutions.

Disassembled the carburetor.
Fuel level was below the lower spec limit, so I adjusted
the float to put the fuel level at the high limit.

I couldn't get the pilot jet out. Decided to leave
breaking that for another day. I did blow air thru it
and used a vacuum pump to suck cleaning solution
back thru it. (water and simple green)
I was afraid to try anything with acetone because of
manual warning about non-removable plastic parts inside.
I can get liquid to flow out all the tiny holes in the venturi.
Let it sit in the ultrasonic cleaner for 15 minutes while
I forced liquid thru every orifice and sucked it back with
the vacuum pump.

Now, much more responsive at high RPM.
Engine sounds good over 25 MPH in 5th gear.
I think that part is doing as well as I can expect for a 125.
Spark plug insulator now has some color to it.

Low RPM sounds like it might be a little rich.
Still detonating slightly around 4K RPM depending on
gear and load.
I cranked the pilot screw out to 3.5 turns
to reduce the detonation. Helps, but
doesn't change if I go further.
Runs OK at low RPM and low or high throttle.
Problem is that it pings at about 1/4 throttle
at low speed.
I'd be generally happy with the performance if I were not
afraid of detonating a hole in the piston.

The tuning instructions that I've read for CV carbs
lead me to believe that the main jet is OK.
The main jet needle is not adjustable.
I think I may need a bigger pilot jet so I can
set the adjustment tighter for low end
and still get more gas in the 1/4 throttle area.
I don't know how to choose the size.

I don't understand exactly what I'm hearing.
My experience is with bikes at least 20 years older,
before the emissions stuff got added.

When the mixture is rich, you get a blubbery/farty
sound. When it's lean, you get a crack-crack sound
from detonation high speed explosion.

What I'm hearing is a blubbery sound at low
RPM and the crack-crack as the engine speed
increases, but the blubbery sound is still there.
The crack-crack disappears as the RPM continues
to increase.
How can it be rich and lean at the same RPM?
What am I misunderstanding?

I could use some advice on choosing a pilot jet.

Is there a trick to getting the pilot jet out?
I had a screwdriver with a good fit and twisted
on it so hard I was afraid I'd break something.

I also had a problem with the float hinge. It's pressed in.
Manual warns not to beak the hinge mounts. Can't tell
which side has the press fit and supporting the wrong
tab can't end well. I banged on the pin as hard as I dared
without success. Float valve doesn't seem to have a problem,
so I left it alone. Wonder if heating or cooling it with freon
will loosen it up. Not sure what the parts are made of and
the relative expansion coefficients.

Anybody got any experience with the 6Sigma carburetor kits.
They claim to design a jet system specifically tailored to your
situation. I hate to drop $50 on a vague promise.
On the other hand, I'd drop $50 in a minute if I had confidence
that it would solve my detonation problem. I'm otherwise happy
with the performance of the bike. A 5% performance increase
and still detonating is not worth $50 to me.

I've read that others had similar lean problems that were never
rectified by dealers.
I talked with two local Kawasaki service departments. Nobody would
admit to ever having worked on an eliminator 125. I'm skeptical
that the 6Sigma people have tried every bike that they claim to support.

It has been suggested that the timing may be too advanced.
I'm not aware of anything I could do to change it???
I'm operating on the assumption that any detonation is a serious issue.
Am I worrying too much?

Advice?
Thanks, mike