Ducati Sporting Club UK > DesmoDue Race Series > DesmoDue - General Questions and Chat > In search of Dallas's Missing ponies

[skidlids]

With Snow white for a front spark plug its certainly pointing to fueling, couldn't see anything that would be giving an air leak, but may well be worth us removing and taking a closer look at the front inlet manifold in case it has a split in it, you'll know exactly what I mean Phil
Maybe take the vac gauges up there next, but they would probably only identify an air leak below the point where the vac gauge connects to

[paynep]

How about checking the fuel pressure? Last year mine was ok when set up on the dyno then over the course of half a season the pump started failing, giving me no power, white plugs and finally a clucked engine come Snetterton.

A quick way is to check that there is fuel coming out of the return pipe, as it will prove there is more than the 3bar regulator pressure....

If that's ok, whip out the injectors and check they're ok, and/or swap front and rear to see if the white plug moves, if its only one plug.

Paul

[skidlids]

Pressure was checked at BSD and given the all clear.
I would also suspect a common element like fuel pressure to cause both cylinders to run weak not just the front one
Already tried another complete set of injectors that came off a bike that was known to be running well.
Maybe its a problem in the harness, is the injector receiving the full signal
The power commander was removed at the same time as the FIM ECU so can't be down to them as its now doing it with just a Magneti Marelli 59M ECU.
Stopped by at Dallas's earlier this evening on the way back from Durham and helped cut a few un-needed wires out of the replacement harness that is going on and just finished making a note of the last few remaining wires we need to connect up.
Once the harness is done its refit the PC3 USB and see about getting it mapped and then see what power we end up with.
Can't see it being the engine but as a last resort I still have his engine from last year sat in the garage, just needs the replacement front cylinder head setup to match the back one

[skidlids]

Hopefully we will soon know if we are any nearer to rounding up some of the lost ponies.
The bike is now up and running on a almost complete different injection system, the only things that haven't changed are the fuel pump, the pressure regulator and the engine temperature sensor.
Now it just needs the PC3 USB fitting and then getting it set up on the Dyno

should all be done just in time for Cadwell

[chris.p]

I have a pressure regulator if you need one?


Chris

[skidlids]

Originally Posted by chris.p

I have a pressure regulator if you need one?


Chris

Thanks for the offer Chris, but I all ready have a few spare, the reason we haven't changed them is because Mark at BSD checked the pump and pressure regulator and gave them a clean bill of health

[skidlids]

Originally Posted by skidlids

Hopefully we will soon know if we are any nearer to rounding up some of the lost ponies.
The bike is now up and running on a almost complete different injection system, the only things that haven't changed are the fuel pump, the pressure regulator and the engine temperature sensor.
Now it just needs the PC3 USB fitting and then getting it set up on the Dyno

should all be done just in time for Cadwell

Well its been on the dyno and the ponies were still missing

While waiting for the Dyno day to come around we removed the forks and stripped them, then binned them and put my spare set in, I usually find they work better when they're straight and don't have gouges in the chrome where they pass through the bushing.
Dispite them being fitted with 0.85kg/mm spings they actually tested at 1.2kg/mm due to the amount of binding going on inside the leg as the spring and pre-load spacer tried to compress through a slight bend.

In a final attempt to track down the ponies before Cadwell, I changed the front cylinder head for the one I had fitted to Dallas's engine from last years crashed bike.
And after checking out the head he's been running so far this year I'm glad we did it.

Here is a pic of two exhaust valves, each from 620 DD race bikes with the engines built by the same people, both from the front horizontal cylinder and both have done similar race mileage.

[paynep]

Originally Posted by skidlids

Well its been on the dyno and the ponies were still missing

While waiting for the Dyno day to come around we removed the forks and stripped them, then binned them and put my spare set in, I usually find they work better when they're straight and don't have gouges in the chrome where they pass through the bushing.
Dispite them being fitted with 0.85kg/mm spings they actually tested at 1.2kg/mm due to the amount of binding going on inside the leg as the spring and pre-load spacer tried to compress through a slight bend.

In a final attempt to track down the ponies before Cadwell, I changed the front cylinder head for the one I had fitted to Dallas's engine from last years crashed bike.
And after checking out the head he's been running so far this year I'm glad we did it.

Here is a pic of two exhaust valves, each from 620 DD race bikes with the engines built by the same people, both from the front horizontal cylinder and both have done similar race mileage.

They look bigger than mine

[skidlids]

Originally Posted by paynep

They look bigger than mine

That'll explain your lack of power then
Must be those late Monster 583 Heads you have fitted

[paynep]

Originally Posted by skidlids

That'll explain your lack of power then
Must be those late Monster 583 Heads you have fitted

Oh, I'd zoomed in on the image

Looks like you picked up a dodgy pair of heads then