Something just doesn't seem right. Perhaps I'm imagining things or overreacting, but I'd like your guys opinion... I keep hearing a rattling noise almost like pinging (sounds like a marble in a paint can), but it occurs at certain RPM's. Giving more or less throttle gets rid of it, and it doesn't matter if it's under load or not. Maybe it's just a loose bolt somewhere?
Sounds exactly like my issue, AgentX. I checked the timing about 5 times, and it's spot on. I might try advancing it anyway just to see what happens. Also, I'm running 100 octane. Just filled up with 91 to see if that makes a difference. Usually when I hear a ping think "is that pinging?", give a bit more throttle and it gets louder, then I think "yep, definitely pinging." This however, is just like you describe. Only certain RPM's, and uphill or straightaway makes it no worse or better. I looked around for things that might rattle, and even held my keys while riding to see if that was it. But it really seems to be coming from the engine.I made some adjustments to my idle screws and now it idle's fairly well and hasn't died or made scary noises like that ka-chunk, though I'm getting some backfires when engine braking so I think I'm a bit rich.
Ace....as in the main rod bearing?.. or other bushings all over?.. or crank bearings?... Ace.. think i read you mention something on ceramic bearing.. was that concerning the wheel bearings?.. or did you replace main crank with ceramic bearings?I been thinking alot on this lately... replacing everything with higher qual bearings.. all throughout... ceram if possible.. slight perf increase?
Backfiring on engine braking means your throttle is closed, and that puts the carb on the pilot circuit.So, that's what you have to adjust. Use your little angled screw.I can't tell you which way to turn it, because it can happen with too rich or too lean. Too lean is more common, but it can happen either way.
The sound your hearing "sounds" to me like a rod bearing to me. ERC