You sure it isnt YEIS ? a black box with nothing in it fits the bill here.

ur right it is yeis

and also it has a 34x on the head of the engine

ill get some pics on later as its going to a mates to have the electrics looked at

many thanks paul

ur right it is yeis

and also it has a 34x on the head of the engine

ill get some pics on later as its going to a mates to have the electrics looked at

many thanks paul

'YEIS' is Yamaha Energy Induction System

A development yamaha made many years ago, some people dont think it does any good, but i think Yamaha probably know best.

Also sometimes known as a 'Boost bottle'