Compression testing - minor detail

[geetee]

Going to run a comp test on my R.

Instructions with the comp tester say to disconnect ignition completely by removing LT cable....

I've done lots of comp tests on m'bikes and always just removed the plugs, put em back in the plug cap and left them grounded on the engine block somewhere so they spark away....

Obviously, you have to remove all 4 to do this otherwise the car starts

Is there any benefit to totally disabling the ignition circuit - or is it just a preference so ur not likely to zap urself with a spark

Cheers
GeeTee

 

[Rishi]

There's no need to disconnect the whole IGN system... Thats probably been printed to cover their backs when it come to Health & Saftly issues...

 

[geetee]

that's wot I thought...... making work for urself me thinks.

Cheers
GeeTee 8)

 

[Fast Guy]

I normally disconnect the ignition system. After all it's only a 2sec job to pull the wire off. Saves you trying to balance aload of live plugs on the engine :?

 

[geetee]

which wire?

Cheers
GeeTee

 

[memski]

Disconnect the distributor -> coil wire

 

[geetee]

I think I can cope with that!

You watch though - I'll break something else

Cheers
GeeTee 8)

 

[Olly]

Remember remember to have wide/full open throttle to get accurate readings :lol:

 

[Websnowbo]

Remember remember to have wide/full open throttle to get accurate readings :lol:

Why???

If your takin the piss then please note, i knew you were and just posted this to gain a post count

 

[geetee]

When we used to do the m'bike compression tests, we always did these with wide open throttle.

I'm not sure if makes it any more accurate - but relieves the load on the starter as it maximises the air intake.

Cheers
GeeTee 8)

 

[Fast Guy]

Remember remember to have wide/full open throttle to get accurate readings :lol:

Why???

If your takin the piss then please note, i knew you were and just posted this to gain a post count

Cos the instructions tell you to.

Probably like Geetee says, the cylinder fills quicker, so you don't have to crank it over for so long, so saving your starter motor.

 

[Websnowbo]

Oh, ok i can see that. But it will not alter the accuracy though. It will just make it easy to turn the engine over. Like you say.

 

[Olly]

So if the engine is compression tested with throttle closed where the hell is the engine gonna get the air from to fill the cylinder to give you a accurate compression reading An engine is basically an air pump

Whoops don't wanna get my post count up again :roll: