Hello all I have my eye on a 2005 CBR 600 F4I. The frame is really good with some very minor scratches! anyway it was for sale for a good price but one thing bothered me! the owner told me the engine was replaced! the guy he first bought it from blew it up so he bought an engine off ebay and installed it! He claims it runs good and seems healthy! he used it for the track a couple of times and it ran good. The guy seemed honest but I would please like to know your opinions. Bike BTW has like 35k miles!

 

If it is a replacement engine, no telling what the milage is. That said, if it starts, runs and idles well, you are probably good to go. I personally pay a bike shop the 80 bucks or so to run a compression/ leak-down test before I buy ANY used bike. Compared to the price you are spending, it is cheap insurance on the purchase.

 

Nothing wrong with it, but i"d try to get the price down a little.