stinkwheel wrote:A different gearbox sprocket won't cause the engine to predetonate. It may however be making you select an inappropriate gear for your road speed , encouraging you to ride with an increased engine loading.
Or outside possability, is this pinking at all? Or could it be some other sort of noise? Check the inside run of the chain for any witness marks where the ends of the pins might have hit something because a 20t sprocket will see the pins coming very close the the end of one of the crankcase studs.
This is how it looks with a 21t sprocket on mine. I had to make sure I had that nut near the very end of the stud then tighten it down from the other side :
As you said, now I`m pushing engine rev much more than before. and It is also helping reduce the pinking sound.
well, Now I know that 4000 ~ 5000rpm is suitable for peak output, but before that, very first time when I bought my bullet 2 years ago, my mechanic told me not to exceed 3000rpm, so I was afraid of that part.
After that, I rebuild the entire engine myself last winter to install the 612 crank. and I checked all of touching point such as bolt stud like your picture. you can trust me.
I think dropping sprocket is also can help reduce pinking sound to relieve the load. however it can solve by increase rev
and Current gear ratio is satisfying to me. so I would like to try another method this weekend. (ex. increase heat range of spark plug)
and this weekend I`ll do check my bike depth / spark plug condition etc.
thanks for read and helping me!
regards,
Lee June Woo