Question edited for clarity.
Question moved to Motorcycles.
It sounds like it is part of the Positive Crankcase Ventilation System, also known as a Breather Hose.
https://www.google.com/search?q=gy6+crankcase+breather+hose
It would be better to know 'year make model', rather than just the engine type.
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ck this site....
https://vxb.com/products/1-pair-of-travel-bag-replacement-luggage-wheels-1?variant=43582765596907₪cy=USD&tm=tt&ap=gads&aaid=adaxXEtq4CiMg
Question edited from street talk to normal English.
Fill up the coolant on your mystery motorcycle, get rid of airlocks, make sure the water pump is working and the thermostat is not jammed shut.
All question need FULL 'year make model'.
Question edited for clarity and written English.
You posted to the category 'Motorcycles', but it is a radio?
All questions need 'make model (what it is)' as the first 3 words of every question.
Normally, the peak voltage will dissipate after a while. Or you can add a load to the battery pack like a 12 volt auto bulb and use some of the voltage for say 5 minutes.
In future cease charging when the light goes green as it sounds like there is some sort of over voltage protection.
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