#1 Importance of serrated washer AUC1928J on SU carbs
Posted: Wed Aug 23, 2023 3:43 pm
After struggling for a long time to figure out why fuel was leaking from one of the intakes and the engine was running very often erratically, I noticed that one of the gaskets under nut 5832 was a non-serrated gasket. Why are they "serrated"? To allow, when filling the bowls, air to escape through the overflow tubes. As a result the level rises and the valve controlling the level can close when the bowl is full. If there is not the right gasket (this was the case with me, a bad perfectly circular gasket stuck even around the nut, therefore completely airtight) the air does not escape and the pump continues to fill the carburetor since the JLM9733 needle does not close the fuel supply and in parallel the pressure rises in the bowl and pushes the fuel into the main jet with all the pressure from the pump! A few small strokes of the file in the joint to transform it into "serrated" and ...problem solved!!! I lost a lot of time looking for why I couldn't adjust this engine correctly so if my adventure can clear up some "mysteries" ..... Happy 
