kz750 ltd h2 1981 ignition coils connections pleas

hi kzr's

i've now managed to acquire a complete OEM service manual for my bike.

q1) on fitting the left coil, you connect to 2 & 3 cylinder plugs. does it matter which spark plug goes to onto the coil connector, top or bottom, or doesn't matter please?

q1a) there are two main harness wires to connect for the left coil. the green and the red wires.
does the red wire go to the '+' spade connecter?
and the green wire goes to the negative '-' spade connector?


q2) on fitting the right coil, you connect to 1 & 4 cylinder plugs. does it matter which spark plug goes to onto the coil connector, top or bottom, or doesn't matter please?

q2a) q1a) there are two main harness wires to connect for the right coil. the black and the red wires.
does the red wire go to the '+' spade connecter?
and the black wire goes to the negative '-' spade connector?

i've looked at OEM manual and the Clymer and it doesn't mention about the (left coil) green & red wires.
it doesn't mention about the (right coil) black & red wires.

i'm assuming that the red in both cases are '+' (positive) and the other green wire (left coil) & (right coil) black is '-' (negative).

I've looked everywhere for the above info, without success.

can someone please advise me.

many thanks

angel

You've got it, red is +, and the coils fire both plugs at the same time, so no difference for top to bottom. Aren't your plug wires equipped with a small band near the end with a number for the cylinders? This is factory.

This might help:

Ignition Coil Primary And Secondary Wiring

Ignition coils on the 80’s Kz1000,Kz1100’s and Gpz1100’s are wired the same, that is as you sit on the bike, the LEFT ignition coil primary(small wires) are two wires, RED and BLACK. The secondary (or sparkplug wires) go to #1 and #4 sparkplugs.

The cylinders are numbered left to right as you sit on the seat; #1,#2,#3, and #4.

For the RIGHT ignition coil, the primary wires, again are two wires, RED and GREEN, with the secondary going to #2 and #3.

The RED wire gets it’s voltage from the run/stop switch on the right handlebar switch pod.

The BLACK and GREEN wires connect to the IC Igniter(if the bike has the Kawasaki supplied electronic ignition) it actually gives the coils their grounds to fire the sparkplugs.

Primary(small wires) side of the coils will read between 1.8 to 3.0 ohms.

Secondary(sparkplug wire ports)side of the coil will read between 10.4K to 15.6K ohms.

To stress the ignition coils, take a hair dryer, heat the coils and see if the ohm readings change from cold to hot . If they do, it’s time to buy new coils.

Keep in mind, the wiring is reversed for the 550’s 650‘s and 750‘s, that is the RIGHT coil primary will be two wires, RED and BLACK with the secondary(sparkplugs) going to #1 and #4.

The LEFT coils primary wiring would be again two wires, RED and GREEN, with the secondary(sparkplugs) going to #2 and #3.

These engines have what is known as a “Wasted Spark” that is, a sparkplug will fire during an exhaust stroke. It does no damage and many other motorcycle engines have this design.

hi motor

thank you for your message!

no this bike was in a really bad state and nearly everything needed to be replaced. the ht leads replaced with new ones. i know where all the ht leads fit, i know the positions of the cylinders. what i didn't know was whether each coil plug connection (top and bottom) was specific for a certain cylinder.

thanks to the kzr's that this is not the case.

regards and thanks

angel

ps i can't find any little white markers for the ht leads, not available here in the uk?

hi mfolks

many thanks for a really informative reply!.. gosh you guys certainly know your stuff!

you kindly mentioned about testing the ignition coils. i don't know how to test these. i've been given a multimetre and i don't know where to connect too for the coils testing. :blush: please can you advise me.
i'm a complete rookie in test components and circuitary.

many thanks

angel

The primary resistance is checked at the igniter lead spade terminals.
The secondary resistance is check at the plug wire ends (spark plug caps removed).
I don't know if you'll get the same reading thru the caps. The factory manual shows the test w the caps removed.

Did you already place the Z1 order? Because they sell the spark plug wire white plastic #'s for the cylinder designation. Also new wires/ coils/ caps/ plugs, etc.

This says KZ900-1000 but look under your bike, should be the same part #.
www.z1enterprises.com/detail.aspx?ID=1570

hi motor

what time is there now? it's 15:04pm here!

We've just tested the new spark plugs & ht leads.
the spark is a very slight slim orange, not a fat blue.
we've checked the spark plug gaps and they're correct:-
0.07-0.08

q) does this mean then that the coils need replacing?
they appear to be the original ones. bit marked etc.

q2) what is recommended on as a good ignition coil replacement please?

many thanks

angel

Check the voltage on your red wire to the coils, must be within .5v of battery voltage. This is a common problem, best fix clean the fuse panel clips that hold the fuses, probably put in at least a new main fuse. Check voltage on both side of main fuse so there is no loss of voltage or less than .1v Help?

8:15am Mountain time USA.

hi

the main fuses have been changed to new ones. the fuse box is in new condition. i'm totally lost on checking the components etc.

as the sparks are really 'just there' and slim orange, not big blue. are the coils faulty then? they're oem old and tatty. time for some new ones?

i'll will see what Z1 has?

many thanks for the info on the #cylinder numbering.

kind regards

angel

Existing coils may be okay.

Start with good fully charged battery.

Assure integrity of cable connections to terminal posts (clean and snug).

Especially assure integrity of ground connection where negative battery cable attaches to rear side of engine.

Loss of voltage between battery (measured across battery terminals) and voltage being actually received at coils usually results from old wiring, weak or loose connections, and crusty or loose connectors.

Good Fortune!

Might be a red wire from harness (switched voltage) instead of a red/yellow wire.

Good Fortune!