Evening all.

As the subject says, another 907ie owner has come into the fold. Had it about 2 months, and it goes very nicely sitting next to the Blue ute. Which brings me to the inevitable questions, as it doesn't run as nicely as I would like.

I have been reading all the posts regarding the 907 (all very good and helpful), and there is the usual that affect this bike. The major problem is the miss at low engine speeds when it warms up. Very annoying. I have:

Fitted the ciggie butt (well, a small amount of cotton wool) in the atmospheric pressure line.
Set the TPS to 150mV when fully closed (it was set to 240mV?).
Changed all the fluids, filters and spark plugs.

I'm still waiting for the Vacuum balancer (a Carbtune Pro if anyone has an opinion?), so haven't quite got to the end of the fuel system setup as yet.

Some things I have noticed, though may have nothing at all to do with the problem (please excuse my ignorance!).

When the ignition and kill switch are turned on, but the bike is not started, the fuel pump runs for approx 10sec and then stops. The pump itself has a cut out at 5 bar (or there abouts), but the pressure regulator for the injectors is 3 bar, so theoretically the pump shouldn't be cutting out from its internal cut out. I have followed the schematic of the electrical system, and can't find any timers that would cause the pump to stop. Is this normal? One of the relays does drop out, so the ECU may be shutting it down?

The horizontal cylinder is running hotter than the vertical. The spark plugs I removed (NGK Iridium), the vertical was well worn, but colour looked ok, but the horizontal had an almost white ceramic insulator, and the earth electrode was almost gone? I have checked the spark plugs since replacing them, and they are following the above patten.

After removing the Throttle body assembly, the horizontal cylinder rubber duct came away with the Throttle assy. Once I got it out, there was evidence of some sort of glue around it. It may have been leaking around the seal? Either way, I have re-glued it to seal it, but this hasn't made any difference.

I guess the obvious thing to do is set the balance up of the Throttle assy and air bleeds (I gather the air bleeds are the screws that sit on the Right hand side and are referred to as "Idle Adjust" in the Owners Manual? Again, excuse my ignorance!).

Other than the low speed miss the 907ie is one hell of a bike. It will probably drive me bonkers over the next few months getting it up to scratch.

Thanks in advance for any help with the above.

Cheers!!!

Welcome nickta

You have a wealth of knowledge on your continent so do not fear your Q's will be answered, those niggles that you have are fairly common and most likely you need to give the bike a good ride out and some gentle fettling. I cannot help re the pump over ride isue.

Out of interest what Exhausts are you running with?

All you need to balance the cylinders is a plastic tube about 6 feet long,some oil and some adapters for the manifolds to make your own manometer. Check the FAQ for how to make one.

The miss could be a vacuum leak or valve adjustment or a leaky spark plug wire again check the FAQ or use the search function. Its all here

I've not had any luck eliminating the miss on my '93 despite trying all the ideas mentioned.

I believe the fuel pump timing logic is in the ECU. In the automotive world the ECU cuts the fuel pump after a period of time if rpm is not sensed. Among the reasons is to not have pressurized fuel present after an accident. This system on the 907 is borrowed from an auto I believe. Regardless the same logic would apply.

Hi Nickta,
you stated the horizontal cylinder runs poor, reading the tale of the plug.
one option can be airleak, as you already sorted out.
the other one can be a faulty injector. you can use a cleaner liquid added to the fuel or have them checked and cleaned at a racing shop or Bosch service.

also valve shimming and timing has to be correct for a ideal running motor.

Bertus

Welcome Nick,

I have one question and one question only for you.

Where the hell are you going to find a bend in the road that will provide any fun at all in the Broome area?

Cheers.

Afternoon All.

Thanks to those who have posted replies. I thought I would add a picture of the 907 and answer the questions too. Also a couple of things I forgot yesterday (CRAFT setting in?). And like all good things, more evolution too.

The 907 has a set of Staintune Mufflers with what looks like the original headers. Another funny one here. Where the 4 pipes of the headers converge, there is a nice plate welded in the gap. It catches all sorts of crap including the odd drop of oil. Makes you wonder? The bike also has a non standard chip in the ECU. No idea what make or version? It does disable the the ECU trimmer. Or maybe I should say the ECU trimmer doesn't do anything, which could possibly have been disabled by the Chip?

After thinking about it last night, it sort of makes sense the ECU cuts the fuel pump if the engine isn't running. Thanks for the reasons for this giarcg! Job number 1264 is getting the injectors cleaned. I head east next month for the footy, so will take them for a holiday to a Workshop there I have heard good things about. It can't hurt.

A couple of other things I have done over the last few weeks was swap the coils and plug leads over (Horizontal to vertical and vice versa). Try and move the fault but no luck. It still looks like the horizontal cylinder is the misfiring cylinder. I was sort of hoping I wouldn't have to get too serious with the valve train to soon. My background is electronics (the real stuff, not the virtual stuff), so my mechanical experience is limited. There's not too many Ducati dealers around here either. Oh well, you get that. Time to learn....

Todays little job was to check the Electrical connections around the place. Mainly the Regulator feed to the battery, the Alternator cables and the earths. They were a little bit of a shock (pardon the pun). A previous owner (I'm the 4th) had cut into the reg output, crimped on a bit of black wire and connected it directly to the battery? The headlight globe was a 100/80W, so fair chance it was blowing the odd fuse? I also checked the Alternator connections (LHS just under the fuel tank). They were black as the ace of spades, and got hot as all get out when the bike was idling. I have cut them both out and replaced the wiring from as close to the alternator as I can get through to the regulator. I measured the resistance of the bullet connectors I cut out at a touch over 2 ohms. Not good! Some 5mm Automotive cable is now in place between the Alternator and the Reg, and the Reg to the Battery. Thrown away the 100/80W globe too, until the misfire is under control.

Oh well, back to the bike.

Cheers.

Nice buy!

My 907 has/had a sort of misfire, very low revs, usually pulling out of the garage... the engine would stop dead and if you were not fast with the clutch and your feet, then the bike would kiss the ground in a blink!

I spoke about the issue with a friend of mine who is veteran mechanic and racer in the Dakar (bikes and trucks) and former VERY good official Ducati mechanic (when he could keep the multi dealer status, he has also the Yamaha dealership) and he mentioned me a "circular" from Ducati saying that there was an "updated Eprom" on the 907, the old version was not "right".

I wonder if your problem is related to the Eprom you have, maybe that leads also to the fact that the Hor.Cyl. is lean?

In my case, shortly after purchasing the bike, I fitted a FBF chip with a K&N filter and a set of Termignonis... did some tuning (valves, CO, throttle assy balancing, etc.) and the misfire nearly disapperared, BUT I also changed my driving and I use a little bit more the throttle whnen I pull out and at very low revs.

With this set up the bike was better but had still some issues, and after some experimenting I ended with the FBF chip, full open airbox with the K&N (quite noisy) and STANDARD pipes; it seems awckard but it is nearly perfect now.

To help at low revs I also fitted a 41T rear sprocket, this way the engine works MUCH better, specially in the tight corners tipical of the Alpine roads; the 41T sprocket did not compromise much the top speed, actually it stretches very well in 6th gear, much better than with the 39T.

Welcome aboard!

Any letters/numbers on the chip or maybe post a pic?

The pump cutout when the engine is not running is indeed standard progamming, nothing to worry.

When you set up the TPS at 150 mV, did you fully unscrew the screws of both valves, or only one? I know that often one of them is forgotten, and since the valves are connected via the sync screw, a dead stop might be a false one.

Setting up idle correct can be quite awkward, but if done properly the bike should drive away from idle as smooth as Dame Edna Everedge skating on ice.

Michiel
http://endless-horizons.net/efi/efi.htm

If it is you who provide info at endless horizon, Michiel,
thx a lot f that!

The chip does not look like the original,
guessing it is a custom one.

Acc to Brad B, one should not snap the throttle shut
when setting baseline, just firmly shut it. Works f me,
w repeatable figures.