Re: Motor bogging at start up low speed
If you are still breaking in the engine, the richer ratio of 2 stroke oil will darken the sparkplug more. A new engine is better on the black side when breaking in. It needs the extra oil.
I suppose you could raise the clip (away from the pointy end) on the jet needle one notch to lean out the fuel mixture. Just be careful. Too lean will do damage. Check the sparkplug color a couple of times during the next ride to be sure it is not too lean.