Ooh Ooh, I got another annoying question(s)! The senario: I'm idling my engine (VTR-250) just after filling with fresh oil and have the bike righted so that the site glass gives me the right oil height. I usually kill it then open up the oil cap and put some more oil into the hole to give me the full measure and restart it with it righted to make sure i have maximum level and not over - so far so good. Just yesterday I didn't bother with killing the engine and just opened up the oil filler cap and whoa....! Almost got covered in splattered oil! So, questions: - Is it a measure of excessive blow-by (read below also before answering) if bits of oil get shot out the hole? - I smelt the air coming out the hole and it did not smell at all of exhaust. I smelt of warm oil (actually quite a pleasant smell). If i have a V(90deg)-twin then shouldn't the air just move around the engine and not rather blow out the oil cap hole? - has anyone tried this? Your results? "below" I put my thumb over the oil-fill hole with the engine idling and it really didn't want to push my finger away. It actaully oscillated my thumb when I totally covered it so I guess i don't have blow by So, more questions? I'm confused now. Each cylinder alternates at TDC so the air volume is static inside the crankcase... so why was my finger getting sucked into (althought very slightly) the hole?