yes it was the longer pushrod that caused the prob. the instruction said to check for 13mm I belive (not the 0.31mm u wrote - perhaps typo). and adjust with gasket shims as needed. I didn't and broke the lever on the pump. I should've checked. Anyway, I learnt.
If you suspect the carb and have the Solex carb -- quick check -- on the left side is the idle jet. It's accessible from the outside. Pull it out and see if it has something in it.
B