got the Kat running

[redkatana]

So why do they mark the plug wires 1234 and the firing order is 1243 yet you plug them in 1234 if that made any sense...i kept putting the plug wires in 1243 and i couldn't understand why it wouldn't run. But it sounds awesome with the gixxer cams!!!

[cale]

The firing order is a description of when the cylinders combust. They don't fire in the same order that they are labeled. This is because the two pistons in the cylinders on the outside (1 & 4) go up and down with each other, and the two on the inside (2 &3) also match. When the number 1 piston is up, so is the number 4 piston. This also means that the number 2 and 3 pistons are down.

So, if number one piston is at the top of its stroke and it fires, both it and number 4 go down, driving 2 and 3 up. Now that 2 is up, it fires, driving 2 and 3 down. So, you see, if the number 3 cylinder fires next it won't be good for the rotation of the engine, since it's down all the way. In stead, the number 4 cylinder fires (since it IS up).

Here is a good illustration: it's a video of some kids pretending to be an engine. Notice how the kids standing in the back clap to signal combustion.

http://www.youtube.com/watch?v=DBMVugRCYfY

Also notice how their engine runs in reverse firing order from ours in that the interior pistons fire before the exterior ones (1-3-4-2). Finally, notice how each piston only fires every other time it is up. That's because this is a 4 stroke engine. When the piston is up and it's not firing, it's venting exhaust gas and preparing to suck in air and fuel.

And here's an illustration of an engine with the cam shaft shown. Our katanas have dual overhead cams, unlike this single one, because we run super high RPMs and need extra valves to get air in and exhaust out.

http://auto.howstuffworks.com/engine4.htm

So there you have it. That's why the firing order is different than the spark plug labels.

-Cale

[redkatana]

thanks, i know how the engine runs i was confused on labeling

[cale]

Sorry, I wasn't trying to lecture you.

Yeah, the cylinders are just labeled 1-2-3-4 for convenience. That way you can say "I have bad rings on piston 3 and a broken valve spring on piston 4" and nobody has to work out firing order before they know which ones you're talking about.

Have a good one, man.

-Cale

[mr.lucky]

dang cale tell him again...