Engine difference? F2/F3
 

I'm getting a deal on a CBR engine for $100! The question is, the seller doesn't know if the engine is an F2 engine, he saids it might be off an F3. Is there any way to tell? Thanks in advance

The wiring harness is needed if its an f3 besides that not really anything

IIRC there are two small water lines coming from the water pump to the back of the cyl head on an F3 and just one on F2's.
A Honda dealer should be able to tell from the eng #,if he knows his job.I know the intake boots were changed but they may be the same size/same place.

The cam chain tensioner is different looking .

Yep,different tensioners.Would expect it to be on the new motor.

I'd like to have a spare motor, not to thread jack, excuse me.

I heard that the F2 has a specific code name (MV9) on some of the parts. I'm going to see if my F2 engine says that. If so, then I may have found the solution.

The F3 engines have a speed sensor by the starter for the electronic speedo but guess on an F2 it could be plugged.

Yes and MAL is F3,can't recall if they actually put it on the cases or head anywhere though.

I believe the cam timing and/or ignition timing is different.