I have a 2003 CBR f4i that only fires on 1 and 4. I was out riding when I suddenly had a loss of power. No FI light came on. Here is what I have done so far, and what I have ruled out.

• (NOT SPARK PLUGS) I have checked each spark plug to ensure a good spark, even bought new plugs for the bike
• (NOT INJECTORS) Swapped injectors 3 and 4 to see if problem followed and it didn't.
• (NOT IGNITION COILS) Moved ignition coils around and problem did not follow.

I am left to believe that it is an electrical problem but do not know where to start, any help would be appreciated.

 

update: after looking into the throttle body on 2 and 3 had a bunch of fuel. I have also done a compression check and all cylinders are the same at about 160.s

 

Have you checked your fuel pressure regulator?

 

Yeah so it turned out that the fuel pressure regulator is bad so I have a new one on the way. Really hope that solves the problem.