125-200cc white stuff on carb slide

My 2009 wr 125 had its first outing today with its new wb165 kit in very wet conditions . After riding for about one hour it started to not rev cleanly at low revs, but would idle. I checked the plug and see it was running rich, so i went to raise the needle to lean the mixture going from clip 3 to clip 2. Whilst removing the slide I see some white creamy type substance, its hard to discribe but men produce it (lol) thats what it looked like to me and it was from the top of slide to about half way down it. I also noticed some water was getting past the cover. Looking at the rubber seal on the cover I can say its not in good condition. My questions is what is the white stuff and how did it get there, and why did it stop reving cleanly after 1 hours riding?

The carb is stock: 38tmx, 4 slide, 480 main, 27.5 pilot

A BIG thumps up for the 165 kit

Ive had the same stuff, just wrote it off as condensation with premix/gas.

thanks for the info

LOL Best description ever. Hahahah

I'd say if you stop gripping your throttle so hard and quit playing with your slide as much, your white stuff will diminish greatly. Or you'll go blind and won't notice anyways.

I knew i was in for some teasing