So, I bought the 675 motor advertised on FB marketplace a few weeks ago. I paid the full asking with no negotiation as I thought it was a fair price, sent the money plus the cost of shipping. The seller said he was waiting for a new cam chain guide which took over a week to arrive. I installed the motor and it ran fine but was difficult to start. (slow cranking despite a new battery) I ran the bike for about 6 miles keeping the revs below 10k and noticed after about 6 miles it was starting to get hot.. when I pulled in, it was starting to rattle and stalled. I re-started the motor to confirm the rattle with my helmet off and immediately shut it off as it was rattling on the cam chain side. Upon inspection, I found a lot of shredded cam chain guide material in the cam chain tunnel and under the rocker cover. The motor has now been removed from the bike and stripped down. The failure resulted from the tensioner material clogging the oil ways and oil pump filter screen resulting in oil starvation and siezure of the crank on 2 of the rods. After checking, I found the chain guide that was installed was for a 2011 model. (this motor is a 2008 model year) I contacted the seller as he said this was the part he was waiting for. He refused to talk and would only communicate by text. He said the motor was sold without warranty and would not agree to a partial refund. Basically because of his mistake, I am out $900 on a motor I never got to use. In my opinion, the right thing to do here agree a refund. (I suggested $500) He has stopped responding to my messages. He is trying to sell other parts here and parting out a bike. He has since blocked me on FB and taken down all his for sale posts there.. His name is Blair Ramey and he lives in Bakersfiled, California. Whilst i understand the risks of buying on line, I live by the "do the right thing" motto, obvioulsy he does not! Thoughts?