Cylinder firing order.

Good morning!


I searched and did not come up with any articles or posts on this- I apologise if I overlooked something. Anyway, I got the KZ650 running and idling okay. I was even able to take her around the block. Unfortunately, however, one or two cylinders are still popping. I gave the carbs two good cleanings and cannot find anything clogged or gummed up. Fuel seems to be passing through unobstructed. I would like to make sure that I have the firing order/plugs attached properly.

If I am looking down on the engine and the shift lever is on the left what is the firing order?

From left to right the cylinders should be 1, 2, 3, 4. Correct?

From the coils L and R what should be attached to what? Right now, I have it the way the bike came to me, but it did not sound like it was firing right last year when I rode it. Can someone help me out? Thanks for any help!

Also, my neighbour pulled the boot clean off one of the wire running to one of the coils. I am hoping I can snap it back on as I just got these coils from pumps and they are/were working great!

Does anyone have a diagram? I downloaded a few of the manuals that I have found here, but none really match my bike perfectly... Thanks!

Welcome to the site.
You're correct, the cylinders are numbered from left to right, as you sit on the bike: 1-2-3-4.

The firing order is 1-2-4-3.

One coil will feed cylinders 1 & 4, and the other coil will feed cylinders 2 & 3. Don't know which coil (left or right) feeds which set of cylinders.

The left coil feeds 1 and 4 the right feeds 2 and 3. Of course that being said, doesn't guarantee that the PO didn't switch the coils side to side sometime in the bikes history. Stranger things have happened.
Ride safe.

Not really sure of the exact firing order, but the 4-cylinder KZs run what is known as wasted spark meaning that each coil will fire two cylinders simultaneously though only one will be on the compression stroke (hence the other spark will be wasted).

One coil fires cylinder 1 and 4, the other fires 2 and 3. Which is which doesn´t necessarily have anything to do with left or right, rather with which set of points (or pickup module if you have an electronic ignition) each coil is connected to.

If you remove the timing cover (right side of engine) and look at the timing plate, there´s a wire coming from each set of points/pickup - if you have the stock points setup one will be green and one will be black. I can never remember which is which, but the coil connected to the left set of points/pickup will become your 1/4 coil and the the coil connected to the right set of points/pickup will become your 2/3 coil. Obviously the plug wires should be connected accordingly. And yes, sitting on the bike no. 1 cylinder is to the left, 4 is to the right.

Edit: Damn, you guys are fast.

Post edited by: OnkelB, at: 2007/06/20 10:50

Thanks for the help, guys! I will try this when I get home tonight and let you know how this goes! Have a terrific day!

If the bike is running and especially if it's idling smoothly, then the plugs are probably wired correctly.
A quick way to check to make sure all cylinders are firing:
With the bike idling, pull the wire off one spark plug. You should see a noticable change (stumble) in the idle. Try that with each plug, one at a time. If you pull a wire and the idle doesn't change, it may be that that cylinder wasn't firing. You can also check the temperature of your pipes where they connect to the engine (exhaust port). But be careful. They'll get very hot, if the cylinders are firing correctly.

Use a spray bottle of water to spray the exhaust pipes to see if they are all getting hot, safest way to do it without sizzling your fingers.. :woohoo: :woohoo:

I would also point out that the coils/wires are labeled 1, 2, 3, 4. So, is this to mean that I just plug into 1, 2, 3, 4? That would mean that one coil is taking care of 1 and 2 and the other coil is taking care of 3 and 4. This is contrary to what I have been told and what I have read. I did, however, find this diagram just a moment ago and it appears to say that 1 and 2 are left coil and 3 and 4 are right. What should I believe? Could the popping potentially be something else?





Post edited by: Deodra, at: 2007/06/20 12:21

Post edited by: Deodra, at: 2007/06/20 12:21

del

Deodra wrote:

I did, however, find this diagram just a moment ago and it appears to say that 1 and 2 are left coil and 3 and 4 are right.

I agree that it appears to say so the way it´s drawn up - however, it is misleading, what we told you is the correct version, one coil does fire 1/4 and the other does fire 2/3.

Could the popping potentially be something else?

When you say popping, do you mean it backfires, or does it just skip a beat? Either way it could be a number of things but look for the easy stuff first.

Could be something as simple as a bad plug, I´ve seen plugs that would fire out in the open but wouldn´t have enough spark to fire the cylinder under compression.
Use the method ltdrider and Milkman suggested and find out which cylinder is the problem. Swap the plug from the problem cylinder with one from a good cylinder and see if the problem moves, if it stays the plugs are likely ok.

Some other stuff to look for (assuming the carbs are ok): bad connection between a plug wire and it´s boot, missing or cracked vacuum port caps (the ones on the intake boots), worn or pitted points or a stuck advancer.

I will check all of these things! After further review I do believe I may have one wire from each coil on the wrong plug. I will double-check when I get home. Thanks, guys! I suppose I am getting ever closer to riding again!

Take off your points cover. The right hand set of points (or pickup coil if electronic ignition) has a GREEN wire hooked up to it. When the crank rotates to where the points fire or where the pickup coil picks up the signal on the crank rotor, a signal goes up to one of your coils on that GREEN WIRE. The green wire is the 2/3 coil and it doesn't matter which side you have the coil mounted. The green wire connected to a coil makes it the 2/3 coil. The left points or pickup coil has a BLACK wire that connects to a coil and that makes the coil the 1/4 coil. Look at ONE of the coils. If the wire from the ignition is GREEN connected to a lug on the front of the coil, the coil should have ignition wires going to the 2 and 3 spark plugs... If black, to the 1 and 4. I am thinking that all four cylinder Kaws that I know of use these colors. If you have a Dyna S ignition, they don't use the correct colored wires... they use little plastic bands colored BLACK and GREEN to remind you which wire comes off which pickup.