Information from the customers

Specification will be the secret and key of the parts business. The parts will be some rubbish if it could not be fitted.  So the feedback from the customer also quite import information for us to improve our database.
We used to suppose GY6 80c big bore engine kits and GY6 100CC big bore engine kits are both only one type.  But some customer report is could not fit their engine. Finally we check and found there will be another version. 64mm valve version  and 69mm valve version both existed.