Re: mercury sport jet 120 hp no fire
English probably isn't your first language, its hard to help from your first post. No spark to all 4 plugs....start with obvious, kill switch....next check switchbox. Do you have a DVA meter?
Or is it just missing spark on #4?
What year is your engine....XR2?....I have shop manuals in pdf, can email you correct one for your engine, very thorough ignition section. Post email and which engine if you want it.