Hi guys,

Just wondering if anyone can point me in the right direction..

My NSR has been running great for a while, but recently developed a problem between idle and 4k rpm. It will bog and seemingly lose the forward cylinder until 4k at which point it picks back up and runs perfectly fine. Reading the plugs shows the forward cylinder running rich, but it seems odd that it would only be affected up to exactly 4k and regardless of throttle position (it idles fine). We've checked the reeds which are in good condition and the power valve function seems normal.

Any ideas?

Cheers
Jam

Always worth checking your inlet manifold for cracks or splits, or even making sure the base is not warped due to over tightening.
_________________
Proud Father of , 05 ktm 400exc supermoto 2018 honda crf rx supermoto