Yup. Opened up the hex, slid out the spring and check valve. Cleaned and polished with the cloth, sprayed the interior down with denatured alcohol, did the twisting cloth thing, put my right foot in, then took my right foot out, then put the mess back together and shook my foot about. I am thinking about doing the dance again tomorrow just to cover my bases.

Result was a bit of knocking, then silent. Then knocking under load, followed by smooth running. Then, while idling, it will knock for a second, then go silent.

Yup. Opened up the hex, slid out the spring and check valve. Cleaned and polished with the cloth, sprayed the interior down with denatured alcohol, did the twisting cloth thing, put my right foot in, then took my right foot out, then put the mess back together and shook my foot about. I am thinking about doing the dance again tomorrow just to cover my bases.

Result was a bit of knocking, then silent. Then knocking under load, followed by smooth running. Then, while idling, it will knock for a second, then go silent.

my best guess is there is still some shist in the valve.