Old plugs

[Miztaziggy]

Are these normal?

Front, with lots of rust






And back, which looks a little shiny as if it is wet?? With oil or something???

In real life, back looks dry, front looked wet around bit of thread

[gafr]

looks like you are burning a bit of oil. plugs should be a nice biscuity colour, not wet, black or grey.

[BigVeeGrin]

front looks like evidence of what gave me a coughing, clanking, spluttering misfire today after all the rain yesterday.

Guess water drains into the plug area via the lead when it's peeing down and collects under the protection bit.

[darkember]

Get new one asap they look awful. As for the correct burn colour the front cylinder is usually set to run a little leaner than the rear. This is will make the front plug have a light grey/off white tinge to it like the one shown in the haynes manual for normal condition. The rear cylinder if the carburation is correctly setup should be a rich tea light biscuit colour as it is designed to run a little richer to keep the cylinder cooler.

[AMCQ46]

Ziggy, they don't look too good, time to change, and need to recheck the rear one after a good run as it shouldn't be wet.

Going by the rust on the front one you also need to unblock the drain hole which runs from the bottom of the front plug out to the front of the cl head near the exhaust. It is only a couple of mm diameter, so not easy to see, but get an inspection lamp onto the front pot and you should find it, then stick some wire up it to clean it out

[Miztaziggy]

Thanks guys

New plugs already in. I just took those photos as I took the old ones out. Will take it for a ride and inspect again.

[tony.mon]

There is a drain hole in the casting for water to drain away from the front plug area.
Make sure it's clear and drains freely.
I suspect yours is blocked or partially blocked, allowing water to gather around the plug cap and insulator, hence the rust.


if you're getting misfiring the plug colour won't be trustworthy, so ignore the front one, and if you have a chance check the new one a week after you clear the drain hole.