The Honda Spada fuel taps have 3 outlet nipples. One large one for fuel transfer and 2 smaller ones, one which the vacuum tube connects to and another one, which points downwards, that usually appears to do nothing at all. Recently a friends Spada began briefly dripping fuel out of the bottom outlet, I've never seen this before but notice Honda fits a drip tray under the petcock. Does anyone know what the function of this third outlet nipple is and what it indicates if fuel is dripping out of it?
It might be for a drain if the vacuum diaphram leak's ? You could alway's delete the the vacuum operated fuel tap and replace it with a manual one, then just turn it off when you get off the bike. Guess you'll need to remember to turn it on again before trying to start it too. Guess you didn't end up replacing it ? https://2fiftycc.com/index.php?threads/honda-spada-fuel-tap.9984/
I'm still in the process of working out the best replacement strategy. I have purchased some VTR knockoffs from China. Its a friends spada that started leaking out this mystery outlet/inlet.. I'm leaning towards it being some sort of breather.
I think my67xr might be on the money. I purchased a fuel petcock rebuild kit for a ‘96 Honda 750 that was leaking from that 3rd outlet. In this case it was the inner rubber diaphragm that actually shuts off the petrol that had a leak. This 3rd outlet is between the 2 rubber diaphragms, the outer diaphragm had no leaks, so when you sucked on it to replicate the engine vacuum it all seemed fine. It seems like the 3rd outlet is there to normalise any pressure when vacuum isn’t there, that’s when the spring takes over, and also lets you know if you have a leaky inner diaphragm.
VT250 Fuel Tap repair kit, $37 inc post https://www.ebay.com.au/itm/HONDA-V...069710?hash=item1a4f82010e:g:cEwAAOSwZtlaOkD2