Smoke coming from top of cylinder(where spark plug goes)??

[yammieman]

hey there. i had to do spark plug chop tests today and re-adjust my air screw. I followed the jetting guide 101 again and got the engine to operating temperature, ran and rode the bike for a bit however when i took the spark plug out(engine stopped), i noticed smoke coming from the hole where the spark plug screws into...is this normal because the engine was hot? or will it have done damage to my cylinder/piston?? It's a 2 stroke Yamaha YZ 250.
i know it may be a bit of a stupid question but I just thought id ask, make sure and know 100%.

 

[arnego2]

could be. I would not do that too often, taking the spark plug out when really hot. Too dangerous for the threads in the head, IMO.

 

[yammieman]

yeah good point...ill wait til the engine cools off a bit next time. if i hadn't redone my jetting/air screw i would've needed to do that whilst on a ride...i had been fouling plugs where ive had to stop and quickly change plugs but just never noticed the smoke before...the bike shop had the air screw all the way in(closed)...bike was idling **** and running like ****...so im glad i changed it but yeah, not sure if the smoke is bad for the piston or not...or if it's just normal and should do no harm

 

[2strokerfun]

I've pulled plugs from hot two strokes dozens and dozens of times. I've never noticed smoke from one. Do you have any idea how many hours are on the top end since it was last rebuilt/new?

 

[yammieman]

yeah, only 15 hours. recently had both top and bottom end done

 

[RM_guy]

It could be that it is running lean and getting hot enough to make it smoke.

 

[yammieman]

yeah, at that point i was running it a bit too lean just until i had the jetting right...i fixed it now though. wouldn't of done too much damage if any at all would it?? was just for a few seconds.
I have tested a spark plug since then and it is a nice tanned brown color so not too rich and not too lean now.

 

[RM_guy]

You should be OK

 

[yammieman]

ok cool. that's relieving to know lol. cheers for that mate :)