kz440 timing advance unit problem

its a twin so there are only 2 spark plugs and there is only one pickup module.... so doesn't the spark plugs spark twice as much as they need to anyways?

thanks

gabeb123 wrote:

its a twin so there are only 2 spark plugs and there is only one pickup module.... so doesn't the spark plugs spark twice as much as they need to anyways?
thanks

Yes, the spark plugs do indeed spark twice as much as they need to.

When the rotor points to the module, the ignition coil's primary winding becomes ungrounded, which causes both spark plugs to simultaneously fire.

The F mark on the advancer is supposed to align with the permanent case mark slightly before the pistons simultaneously reach top dead center.

The spark that ignites the mixture within the combustion chamber that's on its compression stroke is actually doing something.

The other spark within the combustion chamber that's on its exhaust stroke is "wasted."

Good Fortune!

so pretty much it doesn't matter what way the rotor faces(because it can only face 2 ways) right?

gabeb123 wrote:

so pretty much it doesn't matter what way the rotor faces(because it can only face 2 ways) right?

Not quite. One way the spark happens when both cylinders are at the top, as they should be. If the rotor were to be 180 degrees out, then the spark would always happen when the pistons are at the bottom. That's no good.

Maybe it's the fact that both pistons go up and down together that is throwing you off. That type of motor is known as a 360 degree motor.

Honda CB twins are what is known as 180 degree twins. There, one piston is up while the other is down. This is why that type of twin has a really rough feeling motor. The ignition firing is very uneven. The KZ twins (400,440,750) are much smoother (when properly tuned).

This shows you how old I am, but I remember some early Honda's having a 360 crank in I believe, the Benly and Dream motorcycles of the late 1960's.

wait so the piston's dont alternate in a kz440?

gabeb123 wrote:

wait so the piston's dont alternate in a kz440?

Yes, that's why a KZ440/400 doesn't sound like a misfiring engine, like a CB 350... uh, unless it's actually misfiring.

Here's what the crank looks like.

oh ok i guess ya learn something new everyday huh. hey my battery is shot on it so i took the battery out and ive been using jumper cables and a car battery that should work fine just in my garage shouldnt it?

thanks

Yes that should work as long as you don't crank it too long or too often. A car battery can crank much longer than a bike battery, so there is the potential of overheating the starter.

gabeb123 wrote:

...battery is shot on it so i took the battery out and ive been using jumper cables and a car battery that should work fine just in my garage shouldnt it? thanks

For anyone who might be unaware ---

If the car battery being jumped from happens to be installed in another vehicle, be certain that the engine in the other vehicle is NOT running and that its ignition key is switched OFF while jumped to the bike's battery (or to the bike's battery cable lugs).

A car's charging system may quickly overwhelm and fry bike components if the car engine is running while the bike is being jumped from the car battery.

Imo, this admonition is worth emphasizing due to the common practice of leaving the donor car engine running while using its battery to jump start another car.

Never touch any part of the bike with a jumper cable from a battery that's installed in a vehicle with a running engine.

Good Fortune!

no its just a car battery its not even in a car ive been just charging it with like a 6 amp charger.

thanks

Patton wrote:

gabeb123 wrote:

...battery is shot on it so i took the battery out and ive been using jumper cables and a car battery that should work fine just in my garage shouldnt it? thanks

For anyone who might be unaware ---

If the car battery being jumped from happens to be installed in another vehicle, be certain that the engine in the other vehicle is NOT running and that its ignition key is switched OFF while jumped to the bike's battery (or to the bike's battery cable lugs).

A car's charging system may quickly overwhelm and fry bike components if the car engine is running while the bike is being jumped from the car battery.

Imo, this admonition is worth emphasizing due to the common practice of leaving the donor car engine running while using its battery to jump start another car.

Never touch any part of the bike with a jumper cable from a battery that's installed in a vehicle with a running engine.



Good Fortune!

in a friends shop I saw the results of a bike that had been jumped from a running car, FRY PUPPY :woohoo: