kz750-4 spark plugs

Dear fellow KZ riders,

Yesterday I changed this spark plugs to the original specs according to manual: B8ES.





What can you tell about the old ones (BPR7ES) by watching at the picture? The colour is OK?

perfect

yellow square shows heat range of plug...50% of strap is correct and proper.

orange circle shows correct jetting a sooty base 100% around this is great

red shows correct color on porcilen. signs of preignition/detonation are shown here.

Dear 4theKZ1000:

You have made my day the greatest! :woohoo:

It is always nice to hear someone (with real knowledge about subject) talking good things about your bike.

Hope I will find the B8ES's the same way when I take them out in about 600 miles.

Thanks again.

Esteban

Do this for me.....use anti seize on the threads of the plugs before you install them.....hand thread the plugs in untill they are seated to the head dont use a wrench to do this.....then use a proper torque wrench and torque specs to tighten plugs. These bikes are bad for stripped spark plug holes. Do these things and you will be riding not fixing the bike.

Please be very carefull riding

I've had new, NGK's fail either right out of the box, or sometimes later, so if your bike acts up, switch to another sparkplug brand before tearing into the ignition or carbs.....

Sparkplug Cross Index
www.gadgetjq.com/spark_plug_cross_reference_motorcycle.htm
www.sparkplug-crossreference.com/convert/NGK_PN/B8ES/
www.globaldenso.com/en/products/aftermarket/plug/

Yes, I have used a copper based anti-seizze compound and torque to factory specs. Thanks again!

you should adjust the gap, spray them with carb cleaner, then put them back in. after that you can check them again after a while.

4TheKZ1000 wrote: perfect

yellow square shows heat range of plug...50% of strap is correct and proper.

orange circle shows correct jetting a sooty base 100% around this is great

red shows correct color on porcilen. signs of preignition/detonation are shown here.

Attachment sparkplugs.jpg not found

those are white and you know it.

white is god of you, no need to change anything. just make sure they don't get coated in gas, as that will make it hard to drive.


80 kz750h 4-1 exhaust, dynojet fuel + k&n w/drilled airbox.

donthaveakawman taps your shoulder and whispers in your ear(tell that dude not to be a needlejet, those are not that different)

So... at least but not at last... lean or OK? :blink:
Number 1 seems to have a golden brown colour.... if only the four of them were like that...

If it is lean... do I have to change jets? or can I adjust the air pilot jet screw (near the carbs top cover)?

Al jets are factory original.

I have good news for you. If the plugs you show in the pictures are BR7ES and the plugs called for in the manual are B8ES you should not change the jetting or anything at this point. The 7 in BR7ES signifies that those plugs are 1 heat range hotter than the B8ES plugs called for in your manual. That will cause the plugs to retain more heat and cause them to show symptoms similar to those related to lean carburetion. Run the bike with the new plugs and check them to see if there are any lean carb symptoms. Ed

Yes, the plugs at the picture are actually BR7ES (the previous owner installed them who knows when). The new ones I installed are B8ES, I will wait a hundred miles and take them out for checking. Thanks 650ed!!!