Scooterotica

Ok. Talk to me about this spark plug test I've heard a bit about. Something about quarter throttle for a while,engage clutch,turn off by key then Coast to standstill. Apparently do this on quarter,half a three quarter throttle then check plug colour. Advice please.

Oh, reason is I have Honda 205 kit with but changing exhaust to a clubby.

Cheers.

Mark your throttle on the handle bar at 1/4, 1/2 etc.

Find a nice bypass with a lay-by. Run it for about a mile at fixed throttle position, then knock the ignition off and coast to a stop in the lay-by. Inspect your plug for colour and compare to published charts.

Thank you rosscla

It's generally referred to as a "plug chop". It's a way of getting a view of the plug at a particular fixed throttle position. I use a local A road with a couple of lay-bys as Ross suggests. Switch off ignition, pull in clutch as quick as possible and coast to a halt. Ideally you should perform plug chops at several throttle positions, ie, 1/4, 1/2, 3/4 and WOT [wide open throttle]. I do 3/4 and WOT ones on the motorway, just before a slip road exit and coast onto the hard shoulder near the end of the slip road.