J4 TIMING HUB does not match with 84XL037 timing belt. Most of the 28 teeth of J4 TIMING HUB work fine. Only three or four teeth are not correct. I tried it with a higher belt tension but it doesn't get better.
I just received the next batch of parts. The belts fit well on this batch so I am unable to replicate the issue but I suspect variance in cutting equipment and materials. I would recommend using a nylon abrasive wheel along the width of the teeth, polishing not only the OD but the faces and flanks of the sprocket - removing any sharp corners should allow the belt to fit as intended.
I just received the next batch of parts. The belts fit well on this batch so I am unable to replicate the issue but I suspect variance in cutting equipment and materials. I would recommend using a nylon abrasive wheel along the width of the teeth, polishing not only the OD but the faces and flanks of the sprocket - removing any sharp corners should allow the belt to fit as intended.