Hey guys I found a 1999 yz400f for sale on craigslist for $650 his add stated the head need to be rebuilt I emailed him and asked him why he thought it need rebuilt this was his exact response. "Not sure. I did not start it last summer. And now the decompression lever won't engage. Might be able to get it running by pull starting it. I just have not got in to it to much" So he sent me a few pictures and it looked ok ripped seat cover and the plastic was a little beat I asked him his bottom dollar and he said $400. I told him I'd think about because I currently have my cbr600f4i that needs put back together and im not exactly looking for another project right now but this seemed like a good deal and Im sure I can get it running for the right amount of money. In our last email I asked him if the decompression lever was simply not decompressing the cylinder or if the piston was just moving freely when kicked and this was his response. "Usually when I kick it once I have to decompress and now it just kick it and kick it with out the use of the lever." So with out physically looking at the bike and from what he's told me and my little amount of research I've done its either A: The decompression cable is stuck and keeping the exhust valve open which is the best case scenrio or B: Theres a valve stuck and or bent causing loss of compression and possibly putting a hole in the piston scattering small fragments of metal through out the engine : ( worst case. If I were to buy this it would simply be to repair maybe ride a bit and then turn it around for a profit I think I could get at least 1k out of it running. My question is if there is a bent valve what am I looking to spend if its over $200-$250 I;m not sure its worth it anyone rebuilt a head on here for one of these bikes?