Compression testing.. All plugs out or one at a time?

When reading I see around a 50/50 split of half the people saying take the plug wires off and all plugs out to test and half saying just take plug wires off and take spark plugs out one at a time to test (replacing the last one before taking the next out). Then I remembered this forum and figured you guys would know best

All plugs out.
If you use the key to turn the motor over you need to ground the plugs.
Use a jump box or a jumper wire.

The pics are a lead I fixed up to ground out my 3 cyl. motors.

When testing.
Remove all plugs.
Ground the plug wires if you use the key, or use a jump box.
Install tester.
Turn the motor over until the needle stops going up.(usually 5-6 rev)
Record the results.

The gauge? Yours might not read as good as another.
It could be as much as 20# difference from another.
So the results or actual poundage might vary.
Your looking to get the same or real close to each other.

My gauge reads correct. My motors both read 145# on all 6 cyl.(twin 85's)
That reading is for a healthy motor.
If it read any more than 5# difference between cylinders I'd be looking for a problem.

They say any difference of 10-15% is acceptable.
If I had 10%, that shows a problem.

Do the test and post the results.

Can you post a bigger picture of that? Is it just open stripped wire that you stuff in the plug boot on one side?

I pull 'em all out and ground them. The motor spins over a lot faster that way (and produces consistent results. I test and note the readings and keep a log.

Jeff

PS: Some will say "no way" but, for comp tests, it makes no difference if the carb(s) are wide open or at idle.

When I do compression test on a motor with a kill switch or lanyard I just pull the lanyard or turn the kill switch off. Is this not a good thing to do. I figure with now fire there is no need to ground the plug. Let me know if this is not a good thing to do and why.

Pulling the lanyard off is the correct way to do a compression test !!!!

Yes the wire thingy is just stuck in the boot.

I give the test procedures for a general application.
Not all motors have a kill switch.

Some say you need to open the throttle all the way???
Not needed, it will suck enough air through the intake.

Throttle does not need to be open because the EXHAUST ports are wide open on a 2 stroke !

There you go!

Jeff