Plug fouling

[wheels244]

Hello All

Go easy on me - 1st post !!

Ive just bought a 2002 EC250.

Ohlins Forks
Performance PV cover
Gnarly
Pivot pegs
Wavey discs

etc.

I'm very happy with the bike apart from a plug fouling problem.
I've just swapped from an XR400 which was, as you would expect, very reliable.
I knew there would be much more maintenance than my previous thumper. Carrying out the work is no problem to me.

On to the problem.

I've had the bike out twice now, both times on Green Lanes ( trails ).
The 1st time the plug fouled and stopped the bike on a long, slow, downhill section. I had a spare with me and swapped it and carried on.
Today, I fouled the plug twice, again on slow sections.

Can anyone shed any light on this please. I haven't had 2 strokes for over 20 years !

I'm guessing that it is running too rich ? - I haven't touched the bike since I bought it, so I've no idea what settings the bike has, jetting or otherwise.

I've noticed black slooge coming from the PV cover and around the exhaust where it joins the cylinder.

Over to you guys.

Thanks in anticipation.