250-500cc Bog on acceleration

Next question folks: on my new WR250 I did a full tank of 32:1 for break in. Second time out riding it, still with the 32:1 left in the tank, it would bog down when I accelerated. This happened when I would partially open the throttle, but when I would open the throttle to the level of where the powerband hit, that kicked in fine. Its just at the lower throttle levels that it bogged down. Before the third time out, I changed the plug and added 40:1 to the tank, hoping it would get better. Although it did get a little bit better, it was still bogging at lower throttle levels. Im running Maxima Castor 927 for my premix. Am I doing something wrong? Or do I just need to adjust something? Thanks.

Check your jetting/float height is set properly.

My float height was too high. Setting that and dialing in the airscrew cured the bog on my 125.

The float level is usually too low and try raising the needle a notch. Best bet is to replace that Mikuni TMXx with a Lectron. 36mm is best but the 38mm will work fine.

It's typical of a jetting issue, such as the float, pilot or clip, but it might be the 927. I've seen this before with castor based oils and the WR's. Check your jetting and see if you can clear it up. If not, try mixing at 60:1 and see if it clears up.