Ron Hop

Bog is probably not the right word. You can hear it missing in the mid and upper range. It idles fine.

I have a 2005 that has a persistent bog in the right cylinder at mid to high rpm. I might add, that this happened almost overnight. One day it was running fine, the next day the problem happened. It is only noticeable when the bike has warmed up. Here is what I have done so far with no success. 1. Compression test - fine, 165-170 psi 2. Leak down test - fine, no drop after 10 min. 3. Stator test - fine except the lighting circuit, but lights work good 4. checked and rechecked all grounds 5. checked coil, plug wires and boots, replaced with known good ones, no change 6. checked voltage reg, ran with known good one, no change 7. swapped cdi with known good one, no change 8. cleaned carb x3, swapped with known good carb, no change 9. inspected reeds, no defects seen 10. changed plugs with varying heat ranges, no change the problem only occurs after about 10 min. of riding and I am now at a complete loss as where to look now. I thought I knew a little bit about these bikes having had 2 strokes for about 30years now, but this has got me stumped. Any ideas would be greatly appreciated. 2005- 21cc cool head-k&N filters-Paul Turner pipes-run 50-50 with amsoil dominator