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Re: Vespa Reed Valve Fuel Pump

Posted: Fri Sep 27, 2013 6:29 pm
by gimp1971
mines on the reed block above the reeds

Re: Vespa Reed Valve Fuel Pump

Posted: Fri Sep 27, 2013 7:35 pm
by Juti
Here's my setup if that helps you..

Schematic installation picture (source: GSF)
Image

Vacuum connection on my MMW2 membrane:
Image

Mikuni vacuum pump connection in my case:
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- blue arrow = vacuum connection from the membrane
- yellow arrow = return line to the tank (I have a banjo attached next to fuel cap on top of the tank. Mikuni SI main jet inside the return pipe restricting the flow)
- purple arrow = Y-connection
- red arrow = fuel line to carb
- green line = line from the tank (hi-flow tap in the tank)

Also required:
- Mikuni TMX35: smaller float needle valve needs to be fitted. Otherwise it will flood because the bigger original needle cannot take the pressure. I don't know what is the case with Dellorto.
- fuel tap breather pipe which is inside the tank needs to be plugged when fuel pump in use
- buffer rubber between the pump and frame/casing etc. is recommended