250-500cc Anyone know what seal/gasket this is?

My bikes had some hanging idle issues like it’s sucking air and recently noticed smoke coming from here and oil assuming this is the issue but don’t know what to look for for the replacement part. Any ideas? 04 wr250

That's just the power valve actuator rods etc . There will be some smoke and goop in there but shouldn't be heaps . Wouldn't have thought it'd effect idle etc

Then maybe that isn’t the reason lol

try adjusting air screw in 1/2 turn ? How many turns to full in ?
sounds lean .

I’ve been playing with it for days I think I have it at 2 turns out

I had it way down before and it ran good but it was way too low it wouldn’t idle at all I had to keep the throttle open a bit to keep it from stalling when in neutral, I could barely come to a stop before it wanted to die. But any higher and it gets this horrible idle hang where it kinda jumps up and down in rpms and sorta pulls the bike a bit when it jumps. Very hard to explain without riding it

sounds like you need a bigger pilot jet .