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I run ‘em unless it’s super silty. Like others I hit them with a quick shot of Fab1 and roll. Never thought any dirt got through that I could see.

I definitely understand the concern as the quality of the profilters is noticeably lower than Twin Air or other OEM ones I have used. However I've used probably 50 of the pre-oiled disposable profilters on different bikes and have not perceived any dirt getting past them. A caveat is that I do spray a decent bit more maxima FAB1 on the filter before using it. They are coated too lightly out of the package for me to feel comfortable just slapping it in. Using the pulpmx discount code they come out to just under $10 a piece and for me...

Never had any dirt pass through one. They’ve been oiled properly. Generally many riders over oil filters… If you’ve got lots of oil oozing down to the bottom of the air box it’s too much.

Never tried the Prolifter, might have to do that some time. I love the 927 2 smoke oil they have, it smells great at the track/trails and when you go out to yer garage to crack a beer it still smells great.

I've had this ^^^ happen due to a bad aftermarket checkvalve breather I installed on my gas cap hose. Same symptoms you describe exactly. A super easy first check!

Blow in hose toward cap. Air should flow.

When the bike starts acting up, remove the fuel cap and see if that fixes it. How many hours on this bike? Still stock fuel pump and filter?