I have a 91 907 with 60Kms on in with a high flow air filter and F1S exhaust system. Last year the rear cylinder exhaust valve burnt. At 55Kms, I had it completely rebuild by expert from http://www.mbpducati.ca/ in Montreal Quebec because I like this bike so much. By the way, they are very good and I would recommend them to anybody who is looking for a rebuild or extra power. Now, I drove all summer (5000 Kms) and the rear exhaust is RED all the time but the engine is not overheating. I’ve contacted them and they told me that the valve would last many years/Kms before it burnt again since the new ones were ticker and better then the originals. They are racing/dyno-testing those rebuild engines for many seasons without any problem ever if the exhaust are glowing red and the problem is surely not the engine. So the original problem is still there. First I check the valves, they were O.K. Then I bought a stage 1 EPROM from Ferracci; that was not the problem. I them checked exhaust system and intake manifolds; interchanged the following parts: injectors, spark plugs, spark plug coils, and spark plug coil electronic modules. The engine still starts great and has better power them before. Anybody had a similar problem before? What else can I check? I really want to have this bike on the road again next year but don’t want to spend too much more money on it. I’m thinking the P7 processor.

Check the baffles?
If they're clogged and providing too much restriction, I could see where that might make the pipes hot enough to glow.
Surely, it wouldn't be running as well as expected if this was the case though...
Just a thought. :confused:

I would think just the opposite. If the exhaust is restrictive, the flow will drop, and the mixture will go rich. This should lower the temp, not raise it.

If on the other hand the exhaust (or intake) was less restrictive than what the fuel curve was calibrated for, the mixture would go lean, which should raise the exhaust temp. It's also only the rear cylinder, so it's likely something that can be traced to one cylinder.

When you say the exhaust is glowing red, do you mean the pipe itself is cherry red in broad daylight?

Has the cam timing been checked??? How about the ignition timing on the rear cylinder?

That's true DD, you would think it would make it richer, but I've heard of it hapening on cars....if the HOT gases can't excape through the normal egress, the heat's got to dissapate somewhere/somehow. But then, if it was THAT severe of a restriction, it would SURELY be noticable in performance (or lack thereof!) :umm:
But then again, I'm no expert -- especially in the Ducati field!
I was also going to suggest checking the condition of the plug on that cyl to see it is too lean.
Let us know etheriault!

A red hot exhaust pipe is indeed an indication something is quite wrong.

Excessive heat can be caused by a wrong mixture, when the mixture is too lean the combustion temp will rise, when the mixture is too rich the unburned fuel can ignite in the exhaust trajectory (afterburn), also causing a temp. rise in the exhaust.
FYI: if the water temp. sender is defect, the system thinks the engine is too cold, enrichening the mixture to compensate.
If the air temp. sender (airbox??) is defect, the system thinks the air is too hot, leaning the mixture. Both can effect performance and all related effects very much.

It is also possible the exhaust is defect, causing too much back pressure which leaves the hot exhaust gases too long in the system. The heat will dissipate via the exhaust walls.
I can also imagine exsessive heat is caused by a defect in the cooling circuit of the rear cylinder.

My guess is as good as anybody elses, but I'd check the sensors and settings of the efi system very carefully.
Sensor data can be found on my EFI website (see links).

Michiel

Michiel, You can read ECU problems(sensors, etc...) with that flashing light diagnostic box, NOT EPROM !!!!

Anyway 907 Eprom dont function in IE Elephant. Its tested here.

Ehmm,

That's what I meant actually. My point was that the Eprom in the P7 ECU does not hook up to the later model diagnostics (whit the lcd-screen).
To really read the eprom itself you need yet another set of equipment. I've seen the data from such eproms, and I cannot understand anything of it, unfortunately.

Thanks for the correction, Finnpaso. :thumbup:

Michiel