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I think this is still true of Honda, they use a ceramic component on shaft seal. They are extremely difficult to replace the seal without cracking, and the reason people in the know replace the whole cover as an assembly. I would clean weep hole area, idle bike until it's coming out overflow and hold a piece of paper by weep hole to see if it's leaking under pressure. It may only be leaking after bike is off (impeller may be sealing fine under rotation)

I also ran a stock OEM 2019 KTM radiator cap. Bumps you up to a 1.8.

If all you are getting is one drop on startup, I think you are overthinking this. It's not uncommon for bikes to have a tiny bit of wetness around this weep hole. Run it , and keep an eye on it. Rarely does this assembly have a major failure - it just starts seeping more and more.

My 17 always had a black smudge near the weep hole even after replacing the water pump and oil seal. Still ran the bike 250 hours with no issues.... Hondas are bullet proof

No problems man! My '22 was almost exactly the same as well. I would think also if it was a issue I would have overheating issues riding deep sand at Coops etc.

Same issue here as well, basically since new it has had residue around weep hole. However, there has been no noticable anti freeze levels dropping. Currently bike has around 75 hours or so on it and got it in march and havent touched it. I also run the higher pressure cap on it as well. I agree the mechanical seal is PIA to install and not a fan of them.

Both of our 2025 250's accumulate dirt at the weep hole. they both are at about 20 hours now and i havent needed to add any coolant at all so i know its not much. I am not going to fix anything yet, ill keep monitoring the issue. One bike has a Mylers 1.8 and the other stock cap.

Damn, that's expensive. I'm.on Kawi's now but, It makes me feel like a hero to know I'm one of the few people who has properly installed a few of those seals lol. Really surprised none of the bike build/mechanic content YouTube channels have done a proper how to video on installing one.

I would start with a new cap. Sounds like too much pressure, and obviously something has to be wrong. You’ve replaced more water pump seals in 20 hours than I have in my lifetime unfortunately lol. I run engine ice and a twin air 1.8 rad cap in my 25 crf450r.

Reminded me of that Cheech and Chong skit when Cheech’s car wouldn’t start…”have you checked the air in the tires lately?”😂😂😂 For the OP, I’d consider looking at the bearing/etc for the inside end of the pump shaft (nearest the crank). Wondering if it somehow got installed crooked and is side-loading the shaft/seal. Edit: I’m assuming there is such a thing…I’ve never been inside a newer CRF after 08.

Can you store the bike, SAFELY, indoors and see if maybe it’s just cold-contraction? Also, a cap that over-pressurizes the system won’t let the coolant get to the over-flow system.