TOPIC:

Need some direction.....

bout a 79kz1000ltd about two weeks ago because of the engine.
engine is built to a 1198cc with Z4 cams and 29mm
it also has a electronic ignition ( Dyna S ) and Nology high output coils.
Battery fully charge.
#2 CYLINDER RUN AT AROUND 260 DEGREES WILL THE OTHERS RUN AT AROUND 450 DEGRESS
also check the spark and its very lite compare to the other big brite spark.
So this is what i have done.....
1...clean crabs
2...sycronize carbs
3...new plug
4...switch plus wires
5...switch coil
6...check compression...all between 140 and 150 open throttle
7...check niddle movement
8...check main ( 132.5 ) and pilot ( 25 ) air ( 1.5 out )
#1..#3..#4 plug burn like they should( greyish tip... except #2 plug tip is black and little wet
ran out of time tonite.....need ideas what to check for tomorrow

Do you have a vacuum operated petcock? If so, it's possible that the diaphragm inside has a problem and is letting fuel be sucked through the vacuum tube down into the #2 carb causing a rich condition. One way to check is to disconnect and plug up that tube from the petcock and cap the vacuum port on the #2 carb. If you then run the engine with the petcock in the "Prime" position you can see if the #2 pipe gets hot as the other pipes. Ed

650ed.....no vacuum operated petcock
on/off....one gas line to 29mm smoothbores
i also used a motion pro temp gas tank ....same results.
thx

If not already done, would perform clear tube test on #2 carb to determine whether fuel level is within spec.

Special tool isn't essential, as may use section of larger hose or conical shaped grommet to accommodate the clear tube.




Good Fortune!

hey patton.....

yes already done..check twice
why would the spark be not as briteor strong as others...that is what i do not understand

How old are the sparkplug caps? They have a 5000 ohm resistor, that does not age well. To test, unscrew them from the sparkplug wires, and use a multimeter to see the ohm ratings. Before re-installing them, if possible, cut about 3/16" to 1/4" from the end, and then install the caps.

As a visual test for comparative spark quality on #2 and #3 plugs, could attach the plug bases together (eg. tape, rubber band. whatever) -- rendering it unnecessary to ground plug bases against the engine head -- and watch sparks on the two plugs with engine spinning over.





Is there a significant difference in spark quality between the two plugs?

If the plug wires are removable from the coils, would replace them with brand new Dyna metal core plug wires, which come with integrated non-resistor caps, especially the #2 and #3 plug wires.
Then re-test for comparative visible spark quality as described above.

As both #2 and #3 plugs are in the same secondary loop, it's puzzling why one plug would have noticeably weaker spark without blaming it on some defect in the plug itself.

Good Fortune!

well i did not get to do the above test mention above..will do......thx for the input...
did drive the bike for about 15min. ..
1st...bike does not like to idle below 1800rpm
2nd...bike under load.... under 3000rpm sluggish..wakkens up above 3K rpm (not enough street) 2nd gear
3rd...scary fast...tire losses traction
pic of plugs after drive...


left is #1 was on bike already and right #2 new plug ( reason for no carbon builtup)
carbs are 29mm SB 132.5 main..25 pilot...1.5 air jet..neddle ste at..n/a
temps at exhaust.... all were at around 450F except #2 at 320F

Tried another brand of sparkplug ? Maybe a set or of Denso W24-ESU's, or some used plugs to see if it's ignition related.

good idea.

i bout four new plugs...same result.
i have another dyna ignition and will use my original coils from my 77kz1000.
will change one at a time and see what happens

thx for the input

Patton wrote: If not already done, would perform clear tube test on #2 carb to determine whether fuel level is within spec.

Special tool isn't essential, as may use section of larger hose or conical shaped grommet to accommodate the clear tube.

Good Fortune!

I made a special tool for my floats. They are the 33 Miks. I had to find a fitting to fit the float bottom over the main jet. I found one in my junk drawer. Wait for it, here it comes, it is the end piece to a mini mag light. I drilled it, 1/4" piece of brass tubing, 1/4" clear tubing and I've been using this tool for 30 years.
Where there's a will, there's a way. Some times Will isn't around.
Steve