I also have too much time on my hands. Its winterish here now and I am keen to do a compression test on my machine, mainly for future reference.

My big worry is blowing up the HT spark, with the spark plugs having no load. Is this a worry?

Thanks,

Rick G.

The method used in the books tells you to lay the connected spark plugs on the cylinder head whilst conducting the test. This allows them to discharge their spark as if instaled in the engine. In practice this is very difficult to do. You could either join all the spark plug ends together with copper wire and connect this to an earth point on the bike but this is a it labourious. What I did was to make a note of the low tension (12V) connectios to the coils and disconnect them for the duration of the test. I had to do my test twice as after doing the first test and connecting everything back up I realised that I was not holding the throttlet open when cranking and got very low readings circa 105psi. Holding the throttle fully open gave 195psi. What an idiot!!
Anyway, disconnecting the 12V connections seemed the easy option to safely killing the spark and I can report that all is working well having performed the job twice!

I definitely recommend disconnecting the coil power.
Regards,
K-BIKE