I was watching the American youtube channel Lumnah acres and one of his obviously British fans sent him one of those, which wouldn't fit because it wasn't an American thread so he had to go find one himself. It made I chuckle.
I'm with TYA, pedal pivot bush. If it's worn the pin and is now in a slightly different position, it could be hanging up on the wear ridge. It could be an easy fix without getting too involved. If it only needs a small prompt to return, then a return spring could help as well.
Compensating for the wear in the rocker pad, where a feeler gauge bridges across the slot, was to cut the feeler gauge down so it went in the slot. This was in the 70s when you worked with what you had, not fitting new everywhere. Ahh the good ole days. :laughing:
Yes, I know Sodium Hydroxide is Caustic Soda but in the oven cleaner products it's for use in the domestic arena so will be weaker but if left to work it's still effective. For general workshop cleaning I use petrol and or thinners as they are effective, readily available and cheap. For heavier...
Try BBQ and oven cleaner, spray it on and leave it for 10 to 15 mins then pressure wash it off. The active ingredient in it to look for is Sodium Hydroxide. I'm doing a RV8 engine at the moment, which has come up like new.
Colin