Li 150 series 2 with GP 200 engine

Advice required...
Have a 1972 series 2 li 150 with standard GP 200 engine and it has always had a Casa GP air inlet hose fitted but is this correct? or should it have the li type air inlet hose with breather pipe or does it matter. The scooter runs very well as it is set up.
Thanks in advance for any responses.
Lee
Have a 1972 series 2 li 150 with standard GP 200 engine and it has always had a Casa GP air inlet hose fitted but is this correct? or should it have the li type air inlet hose with breather pipe or does it matter. The scooter runs very well as it is set up.
Thanks in advance for any responses.
Lee