Fuel pump

discussions specific to the 906 Paso
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Giscard
Posts: 120
Joined: Thu Apr 28, 2011 2:56 pm
model: 906 Paso
year: 1990
Location: Cardiff UK and Dordogne France

Fuel pump

Post by Giscard »

So my newly acquired Paso which had been in hibernation for a few years was treated to a new starter motor, new timing belts, oil change and some re-wiring as well as completely new fuel pipes all round.

I pressed the button and it started virtually straight away and sounds great. I haven't taken it out yet as I have an oil pressure switch to replace before I am completely confident that it is all OK.

However, and there is always a however, I have noticed that the fuel pump seems to be working all the time. It does cut out or become less noticeable if I turn the fuel tap off but otherwise it is ticking away constantly. The bike has the Weber carb and it still has the restricting jet in the "Y" piece.

Is this normal ?
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paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: Fuel pump

Post by paso750 »

yes, it is. The pump runs as soon as you turn the ignition switch on. Do not let the fuel pump run and close the fuel petcock as the pump will run dry which could damage it.

G.
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ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: Fuel pump

Post by ducinthebay »

The Paso, and the Sport, were built in the odd time that fuel pumps started to be used, and fuel petcocks were still in vogue. Its a bit redundant that our bikes have both. No real need for the petcock with a fuel pump. I replace my fuel petcock with a banjo bolt taken from a Weber. And Yes, the fuel pump runs all the time.

On the other hand, I have never quite figured out what the jet in the return line is supposed to do. If anything, it should be in the feed line to help keep the pressure down. But since I don't have a weber, I can't say what the ideal is.

Cheers,
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
User avatar
romus
Posts: 135
Joined: Wed Mar 25, 2009 12:06 pm
model: 906 Paso
year: 1990
Location: Brisbane, Australia

Re: Fuel pump

Post by romus »

ducinthebay wrote:...On the other hand, I have never quite figured out what the jet in the return line is supposed to do. If anything, it should be in the feed line to help keep the pressure down. But since I don't have a weber, I can't say what the ideal is.Cheers,
This is my understanding of the effect of those jets:
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Warwick - on a learning curve and on a
Ducati Paso - Soul of a thoroughbred :P
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