Clogging J-Head

[Capt Jack]

So my j-head has decided to start clogging. I have switched to new filament, but it had been printing just fine. Now, it gets bound up inside the j-head. I noticed that the bowden tube on the printer was full of "filament dust" because the feeder motor was grinding away at the filament since it wouldn't go into the j-head.
I tried to manually push some filament through, and it was VERY hard to do.
I've cleaned out the head with wire and can't find a clog. I've disassembled it and I can see through the j-head (through the hotend from the top). Should I soak it in acetone? Do I need to increase my cooling on the PEEK portion? Reduce print temp?

For some reason I feel that I may need more PEEK cooling.

[Polygonhell]

Is it PLA or ABS?
I'd start by printing 10C hotter, PLA can be all over the place in what temperatures it will reliably print, I had one roll of particularly uncooperative Chinese supplied PLA that would't print reliably under 230C, for point of reference the stuff I usually print, I run at 185C

Assuming you have a genuine J-Head, you need some, but not a lot of air blowing across the peek, I run mine (when I still use it for PLA) with just a print cooling fan, the reflected air is enough to prevent it jamming.

[Capt Jack]

Sorry, forgot to mention that this is with ABS. And it is a genuine J-Head from hot ends.com. FYI, I usually print ABS at 225c.

[Polygonhell]

The PEEK fan is largely irrelevant for ABS, it simply doesn't behave he same way as PLA when it transitions from solid to liquid, either there is some foreign body in the hotend, which does happen occasionally (somtimes you see bits of flashing from machining, or small particles that were in the filament), or more likely you just need to print a bit hotter, 225 is pretty borderline for ABS.
See if it behaves the same way at 240, if that works, drop the temperature back down a bit, if not and you have other filament to test, try that, if that fails it's time to strip down the hotend and see if there is something in there

I actually like to print ABS closer to 245 because the layers bond very much better, but I'm not using a hotend with PEEK when I do that.