Have you got all the parts needed ..? If you have bought a second hand Scott oiler you will need a small t-peace pipe that needs to be fitted into a vacuum pipe.
Basic parts needed are the unit , a long black vacuum pipe (this fits into the top) and goes to a source of vacuum, a t-peace, a long clear pipe that fits at the bottom of the unit , this goes to the chain and of course some cable ties to fix the unit somewhere and the pipes.
For your info a good source of vacuum will be on the throttle bodies .