If you still have that motor, I really suggest you open it and take a look at the bearings on the crankshaft and pistons cause thats the noise I heard on my motor and when I opened it my bearings on both were obliterated and if it ran like that long enough it could have grinded down the metal that the bearings cover. If it has this type of damage then you have been ripped off cause that motor would be useless. Sorry to tell you.
