Don't think that it is over pressurisation per se that is the problem. More the massive pulsing of the pressure due to the sheer size of the pistons. I've got a catch tank fitted which the vent that normally feeds into the inlet between the filter and butterfly is routed to. I'm still getting oil mist out of the breather on the catch tank despite fitting a 2.5mm restrictor in the line to it similar to the standard arrangement and filling the tank with explosafe foam. Might need to fit a catch tank to the catch tank...
At least it has stopped drooling oil down the front of the engine from the air filter. One dribbbling idiot per three wheeler is more than enough!
crazy2