04 YZ 125 compression

[Need some help]

Hey, had this Yz for a little while now, was fooling around and when I crank the engine over I think I hear a little puff of air from the air box, would this cause low compression, how to fix? Thanks a lot...

[YZDOC]

2 hours ago, Need some help said:

 

Hey, had this Yz for a little while now, was fooling around and when I crank the engine over I think I hear a little puff of air from the air box, would this cause low compression, how to fix? Thanks a lot...

 

Normal. the cylinder compresses and the crank case bottom compresses. True compression mus t be tested in one or two ways. cold engine, heated to temp engine. WOT and kicked through a few strokes with gauge in the sparky hole. 

[Need some help]

Alright thanks