I just bought a '98 CBR 600 F3 with a blown engine. I bought an F2 engine and swapped them out. I can get the F2 engine to run with the aide of starting fluid. It seems to run fine for a short period than begins to exhibit signs of overheating. The temperature gauge is reading that the engine temperature is fine though I'm not certain of it's accuracy. I have not ridden the bike or run it hard on the jacks and I have an extra sensor that was originally from a hole in the F3 engine that does not exist on the F2. The ignition seems to be functioning, but the fuel delivery is questionable. Is this sensor a crank angle/position sensor? The carbs also seem to be fine. Any help would be great. Thanks.[:@]

 

I believe the radiator is that same on them, have you checked the whole cooling system? And maybe the cdi, did you keep the one from the f3? That might do something weird I'm not sure though if they are the same or not. I have a f3 tank on my f2 and it doesnt have the vacum hose that was on my old tank but I still have the connector on my engine so I know the engines must be different. How about the ignition coils? Check your petcock too I guess. I would say however that if you have an f2 engine making sure the rest was compatible is the way to go. If you need anything for the f2 engine etc. I have most of that stuff from my last bike still that I would part with for a small amount of cash.

 

I'm sure you probably knew this but make sure you're using the right ecu for the motor. The 98 ecu probably won't run the f2 motor well.

 

the extra sensor is for the speedo the f2 has a mechanical speedo to the front wheel the f3 has thal speedo sensor

 

I actually ran an F3 CDI (ecu) on my F2 with no problem. I don't know if there is any difference, but it ran the same for a few hundred miles.

Tim