Forum

[Barry N]

I recall seeing a diagram somewhere, of how to trim the flat end of the duckbill to improve its action. Buggered if I can find it! Does anyone Anyone have any knowledge of this?

Out of interest Paul, do you use the duckbill on your racers, or do you have a different arrangement? (I refer to the normal outlet at the base of the barrel, not the later "lash-up"!).
Thanks.

[Mark M]

Barry, you just cut it back so the flat bit is 3/16th of an inch long. I think that's the correct measurement, I'm sure someone else will confirm or not!
REgards, Mark

[Mickey]

Dunno if it improves its action but the trim as suggested by Mark does stop it 'quacking' (serious comment as any who've heard the noise will know!)
REgards, Mick

[simon]

I'm thinking of installing Pcv(?) valve on mine. The duck bill was already a bit perished ( the motor spent a long time under a rude shelter in the countryside before i cleaned off the guano and brought it back to life) and so I made a nice brass coupling and put the shortened duck bill on a copper pipe extension. Looks ok but I don't think it's doing much to maintain a crankcase vacuum. I can see nothing wrong with the concept of a rubber valve other than I thing something more mechanical would be better.