Yeah, the Venhill cables are bigger than stock. In the kit I got there was a reducing ferrule that stepped down to fit the dellorto fittings. I used a section of shrink tube around it to keep all the bits together.

Cheers.

Another update...

Temperatures reached above freezing today so I decided to take the Ducati out for a run. Unfortunately despite specifying smaller needle valves as a precaution, the pump totally flooded both carbs. I replumbed the pressure regulator into the system and everything ran fine.

I think I'd like to run without the pump, as I don't see it bringing anything to the party, except complications.

Do I just remove everything that's currently inside the tank? What about the wiring? What about the fuel level sender? Can I just run a wire to that?

Did you keep the return line ?
If you remove the fuel pump you may notice it when the fuel is low and maybe also in some driving situations. I`d keep it.

G.

Like G said. Running with the pump, and the return line, you will end up with a much more constant feed to your carbs over the range of your tank. So even when the tank is almost empty, you still have the same pressure at your carbs as you do when the tank is full. The pump also acts as a petcock when not in use. I eliminated the petcock on mine 5 years ago, and it doesn't have a flooding problem. The pump and return will also do a great job of mixing your fuel, if you use any octane boosters, or Sea Foam or other additives in the tank. A pump makes the system more stable over a wider range of operation. I also encourage you to keep it.

If you are flooding the carbs, there is some other problem, and that should be fixed. Its not the fault of the pump.

Confirm the lines in your tank. The vent line is next to the petcock. The return line is the lone nipple a couple of inches forward of those two. (as I remember) Can you take a picture of the bottom of your tank?

Cheers, Phil

Thanks Phil & G for the replies.

Tank plumbing is standard and was working fine with the Weber - albeit with the fuel pressure regulator set to 2 psi. I'd assumed that the regulator wouldn't be needed with the Dells as per your setup Phil, but even with the return line in the system the carbs didn't like the amount of pressure they were getting from the pump. With the regulator back on and still set to 2 psi everything's fine...

I spoke to Eurocarb (who supplied the Dells) and they reckoned that even with the smaller needle valves the pump was still putting out too much fuel pressure for the carbs to handle. It's all new kit so I can't see a problem with the Dells, and as they're behaving now the regulator's back on I figure it was just a question of excessive fuel pressure.

I take your point about the benefits of keeping the pump in the system and will keep things as they are at the moment - not least because if I remove the pump etc. there's no easy way to reinstate it!

The bike did start easily though (once the regulator was in) and revved beautifully with no flat spots, so I'm pretty pleased with the upgrade so far - just need summer to come along for a full road test!

Hmm, I didn't have the same problem, but then again, Ducati made lots of different variations.
In the Paso, there was a jet jammed into the return line to restrict the fuel and boost the pressure to the carb from what I have heard on this site. I would assume you replaced all of the lines on your bike, and the jet is no longer in your fuel line.

Do you see fuel returning into the tank when you turn on the key and look into the open gas cap? In my system, the most pressure that the carbs sees is basically the 12 inches or so of head between the float needles and the return line in the tank. The amount of fuel passing through the overflow is considerable. You can reduce the amount of pressure the carbs see a bit by how you arrange the T in your line. Make the straight through flow from the pump to the overflow(the top of the T), and the bottom of the T goes to a second T to split to feed the carbs.

But if a pressure regulator makes it all work, and you have one already installed, then all is good. Now, on to balancing, and a summer of riding.

Cheers, Phil

To confirm if the return line is not plugged, you should be able to simply attach a tube and blow through it. It should be like blowing through a straw. Almost no restriction. After that, you can attach the line from the petcock to the return line straight away and confirm that the pump runs fine and the gas circulates in the tank. You can see it with the gas cap off.

If you are connected to the vent hose, none of this will be true.

Cheers, Phil

according to a post in the 906 forum there is a 60 Dell orto jet in the return line. The parts catalogues of 906 and P750 confirm that.


The parts catalogue of the Sport (TAV.29) shows a 120.

Fuel hose setup is shown on p.21 of the user manual.

G.

Thanks again guys...

Just to confirm - no jet in return line, and no blockage - blew air through return line and could feel it coming out of vent pipe.

Agree with you Phil - if it works OK with the regulator leave well alone and worry about something else!

Latest news...

Had the bike tuned by Rich Llewellin, a local guru who specialises in Ducatis and has won awards for his race-bike preparation. Needed to swap out the needles to get rid of a weak spot in the midrange, and it turned out that the small K&N type cone filters were strangling the bike's breathing throughout the rev range (red lines on chart). The bike now wears small 45mm trumpets and is giving nearly 65bhp at 8500 with a near linear power delivery. Torque peaks at 45ft/lbs, but runs pretty flat from 4000.

When new, these bikes made 62bhp fitted with the Weber, so I'm very impressed that my 23 year old bike is giving more power with such a smooth delivery. Fitting the Dell'Ortos wasn't cheap, and getting them running right involved extra expense, but I reckon I've got my bike running as well as it ever will.

Daniel, that`s a nice curve. I figured the filters were very small, but are you now riding with no filters at all ?

G.

Thanks G - at the moment I'm just running with small intake trumpets with gauze screens.



I would have preferred filters, but I've run my Guzzi without filters for years and the the bores were unmarked when I stripped it at 60,000 miles so I'm not too worried about increased wear - the weather here's so damp I doubt I'll get any dust or sand in the engine. I suspect I'm not going to get the midrange that Phil and Maico get with their long intake tracts, but I'm really pleased with the way the bike's running.

I do get a lot more intake noise with the trumpets though - not bad at all!