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digiplex in combination with vacuum fuel pump

Posted: Mon May 04, 2015 8:11 am
by Brutus
Gents,

Last couple of days I have had a go at the fuel pump. Installed the vacuum pump from a Yamaha and altered the fuel lines. Btw, my Paso is the Cali model with the digiplex. As you will probably know the digiplex is activated by the vacuum from the manifold. Two tubes are connected to the manifold, see number 49 below. These two tubes are joined together with a plastic T and one tube will continue to the digiplex.

Image

In my new setup I only used one connection for the digiplex (mainfold vert cyl) and one connection for the fuel pump (manifold hor cyl). My question is if this will effect the timing advancement from the digiplex. Don’t really know if the vacuum of both sides are needed.. Like to hear your opnion :thumbup:

Re: digiplex in combination with vacuum fuel pump

Posted: Tue May 05, 2015 8:06 am
by Brutus
Here some pictures of the vacuum pump modification. Return line to the tank is eliminated. Startup is much approved. I'll have to test the setup of mains, idle jets etc. again

Re: digiplex in combination with vacuum fuel pump

Posted: Tue May 05, 2015 8:16 am
by Brutus
Here the new lines installed. The orange line is the vacuum from the right side of the manifold to the pump. The blue lines supposed to be the flow of fuel from tank to pump to weber.
Léon

Re: digiplex in combination with vacuum fuel pump

Posted: Sun May 10, 2015 9:08 am
by paso750
nice job. I don`t think it makes a difference for the Digiplex if it is only connected to one side of the carb manifold.
Afterall there might two connections only because of the necessity to connect a carb balancer.

G.

Re: digiplex in combination with vacuum fuel pump

Posted: Mon May 11, 2015 9:03 am
by Brutus
Tx Gerhard,

I couldn't resist to have another go at the manifold. Below the current setup. Drilled a hole and fitted a third tube for maximum vacuum to the pump. I was considering to drill out the m6 bolt as shown in drawing above, nr 56. As you probably will know the left one goes through the manifold into the channel. I have a lathe, but this small tubing is a b%tch to create myself.

Re: digiplex in combination with vacuum fuel pump

Posted: Sat May 16, 2015 5:29 pm
by Brutus
Gents,

This is how she runs right now. Pretty pleased with the result. She starts at the first turnover and she responds better between 0-3500 rpm.

https://youtu.be/1wynNtc5p3g


Ducati 750 paso Cali model

Ignition:
- Stock Digiplex, stock connection vacuum lines to manifold
- Stock flywheel and pickup sensor
- Ducati 996 coils, added superseal connectors to wiring loom
- Red ngk spark plug wires and caps
- iridium spark plugs ngk DCR8EIX, gap at 0,9mm

Fuel supply:
- stock petcock
- universal fuel filter
- vacuum Fuel Pump For Yamaha (XVS125, XVS250,TDM850)
- extra vacuum line between right side manifold and fuel pump
- homemade bracket for vacuum pump

Weber:
- idle jets 60
- main jets 145
- air correctors 175
- idle adjustment screw 4 turns out (4 x 360degr)
- air adjustment screw: left closed, right approx 1 turn out
- float level 43mm (with gasket)
- stock aux 3,5 venturi
- aftermarket K&N airfilter