My bike started misfiring under load on my way home from a day trip. The spark plugs are reading lean but she is properly jetted. Cleaned from the fuel tank to carb, repaced plugs and still runs the same!
Any idea's?[&:]

 

The next place I would check would be the rubber carb/manifold boot and the manifold seals. An air leak here can cause what you describe.

 

Did you check the plug wires? If it's an older scoot with factory wires .............

 

Like cHarley said, check the intake seals, spray wd-40 on them with the engine running, if you hear a change in the running then their's an intake leak. And exhaust leak can cause the same symptoms as well, so check that out too. How long ago has it been since the jetting was done, and why are you convinced the jetting is correct? Clean out the carb, the jets could be slightly varnished up. Another possibility is fuel, have you purchased gas from a different gas station lately? Try another brand of gas if you can. Citgo gas is one gas known to cause a waxy type build-up(simular to varnishing) in carbs because they skip a step in the refining proces. Shell is the best if available. The possibilities can be almost endless, but start off with the simplest things first. But since you have white plugs, it's a pretty safe guess to say it's most likely it's fuel or fuel intake related.

 

Not to steel the thread, but ditto on the Shell gas!!!!