- Sun Jul 19, 2020 11:24 am
#91568
What can cause valve seats to loosen - and I have first hand experience of this - is letting the engine slog up a long hill in a high gear, preferably two up, getting everything nice and overheated while beating the crap out of the big end, right before a long descent straight afterwards, with the throttle shut. Halfway down the hill, there will probably be a horrible, very loud sound like pinking, only much worse - this will probably be the exhaust valve seat jangling around in the cylinder head. It was the only time I rode a 500 Bullet like that, while on a run with the REOC near home and I thought 'when in Rome' and plodded around with everyone else. As luck would have it, I realized what was happening, after seeing the exhaust system was still where it should be and not jangling on the road surface and causing the terrible noise. I changed down, opened the throttle and applied the brakes while going down the hill until it sounded more normal and ran properly again, then I took it easy for a mile or two before stopping and letting the engine cool for half an hour or so, before riding home much faster!