Need help!. About a month ago while riding my 2010 660z , I rode over a speed bump (maybe 10-20kmph, luckily) when there was a noise in the engine and the engine locked up. Mileage = 22000km.
First thought it had seized, then I noticed that I could turn the motor backwards to a point and it would jam up and then forwards again to where it jammed again (Est about 60 degrees) from one point to other. But couldn't turn it over a complete revolution.
A hell of a lot of stripping later, engine out, head and barrel off, I thought I found the problem and that cam chain seemed to be catching on something around bottom sprocket. Because after guiding it and turning the engine slowly, suddenly the engine turned over freely again.
Has this ever happened to anyone else?
To cut a long story short - I reassembled everything, motor turned freely by hand, started bike, it idled a few minutes and did same thing again.
I'm totally baffled and frustrated!
Yesterday I have stripped out magneto to check cam chain and lower sprocket behind it. Only to find out chain isn't fowling anything as per my original thoughts. Chain and sprocket is fine.
I removed timing chain completely and tried turning over motor with no joy. crank is still turning backwards and forwards as before between 2 points. Any thoughts? Can only think its a bearing failure.