Oilfiller cap mystery

[F.vanDalen@LR.TUDelft.NL (F. van Dalen)]

Oops! I forgot to mention: my B is '69 model, the only emission control is a 
tube running from the crankcase vent filter back into the intake manifold.

Thanks for bearing with me,

Frank van Dalen

> Subject: Oil filler cap mystery
> 
> 
> I don't think there is an actual problem here, but I'm just dying to know why
> lifting the cap increases RPM. Any comments welcome,
>