how do you know when you blew a head gasket?

[ranger400ex1994]

i have a 2002 400ex that is a 11:1 compression piston in it. now it dosent feel like i have lost any power. but i just noticed that were the head gasket is it looked wet but not very wet. now it might be from changing the piston and cam but i was just woundering?

[FoxMxRiders]

check the cylinder compression and if the gasket have a leak of air when the engine run

[ss440ex]

Clean the area with some carb cleaner,and run it.
See if the leak returns (or oil seap).
I had one that did a little on the L/H side and it ran great
and still lasted for years.