is this supposed to do that on a vf 500 f2

just opened the dipstick on my vf500 f2 while it was running for the first time. (first time opening while it was running as opposed to the first time i opened the dipstick to check oil) and there is a lot of pressurized air coming out. is this the norm? sum of my mechanically minded friends reckon its bad, sum say its supposed to be like that. leaves me wondering which of them knows as little as i do.

any help on this matter would be muchly appreciated

 

Yes.

Besides the actual engine components and engine oil inside your engine's crankcase there's also air in there too,and as the pistons move up and down they pump that air around. That's what you're feeling when you open your dipstick while the engine is running.

You also get what's called "blow-by gases" in the engine too. Blow-by gases are some of the combustion gases which inevitably leak past the piston rings during the compression stroke and end up inside your crankcase. All engines do this,that's why engines are equipped with a crankcase breather system to relieve the pressure that gets built up inside the engine. Crankcase breather systems do exactly what their name implies,they allow your engine to "breath" while it's running.

FYI Pete,it's not really a good idea to open the dipstick with the engine running. Check your oil with the engine turned off. If for some reason your crankcase breather system was blocked or even partially blocked the pressure inside your engine would build up,and when you remove the dipstick you could end up with a face full of hot oil. Ouch!!!:scared:

 

Some pressure is normal, but excess pressure means bad pistons, rings, or cylinders and usually shows some smoke from exhaust.

Since it's a 500, you're right to worry. :behindsofa: