Testing spark and compression

[Guest]

For compression:

"Do remove the tank, pull all the plugs and disconnect the inlet power to the coils."

-Am I removing the tank completely and disconnecting the hoses from the petcock?

-What the heck is the inlet power to the coils?

For spark:

Do I just unscrew one sparkplug, re-attach it to the wire and crank the engine to see if I get a spark against a fin?

Thanks,
Mike

[NickNoo]

For compression :

Yes - remove the tank completely and disconnect the hoses from the petcock.
The inlet power to the coils are the live wires going into the coils - its best to remove both (black and orange wires).
Pull all the sparkplugs. Dont forget to keep throttle wide open while checking compression.


For spark:

Correct !!

[UncleMike]

For compression :

Yes - remove the tank completely and disconnect the hoses from the petcock.
The inlet power to the coils are the live wires going into the coils - its best to remove both (black and orange wires).
Pull all the sparkplugs. Dont forget to keep throttle wide open while checking compression.


For spark:

Correct !!

Okay.

More questions:

Why doesn't the manual mention all that? It just says to pull the plugs and screw the tester into one cylinder, open throttle and crank?

Is the bike gonna start when checking the spark? Or will removing one plug prevent that?

[renobruce]

I don't remove the tank. I simply pull all the plugs, throttle wide open, and test one at a time. For the spark test, lay the plug wires somewhere where they can't arc and hook up one sparkplug at a time and test.

[UncleMike]

I don't remove the tank. I simply pull all the plugs, throttle wide open, and test one at a time. For the spark test, lay the plug wires somewhere where they can't arc and hook up one sparkplug at a time and test.

Got it.

Excepting the fact that everything on the damn bike that the wires can reach is metal!!!

[renobruce]

The empty plug boots probably won't arc. Just don't lick your fingers. :-D

[UncleMike]

The empty plug boots probably won't arc. Just don't lick your fingers. :-D

"Probably."

I'm gonna write this down in my bike journal so they know what happened when they find the body!

[renobruce]

You could put a piece of electrical tape over the empty boots, or lay them on a piece of cardboard.

[UncleMike]

You could put a piece of electrical tape over the empty boots, or lay them on a piece of cardboard.

I was just kidding, I'm much too reckless for that!

Got a spark on all four plugs. I don't know about "nice, fat, spark" as I have nothing to compare it to, but it was there and it was frequent.