not smooth speed till 70km/h, fuel consumption 1:12

FDT · Post by **FDT** » Sun Apr 23, 2006 12:19 pm

Hi,

I am a happy owner of a 907, but my bike doesn't run smooth in city traffic (up to 70km/h). It holds in when I try to drive a constant speed. A lot more when the bike is cold. When air temp is above 20°C it gets less, but in the spring in the Netherlands it is not often so warm. The fuel consumption is 1L:12km. I use the bike daily to work (2x ±30km).
During a service at a duc specialist, they calibrated the throttle vavles and the throttle valve sensor etc (they told me the enigine was much to rich), but it only helped a little bit. I checked temperature sensors, air pressure sensor, battery they look fine to me. I will go back to the specialist (but didn't had time for it, but has anyone an idea what can be the problem.

Oh, I am owning a 907 since end of last year. I had a Paso 906 about 8 years a go. I never got really used to the handling, but the 907 is fine and I like the shape of them.
I still own a Moto Guzzi Lemans 1000 '90; (it will be sold).

Rogero · Post by **Rogero** » Mon Apr 24, 2006 6:23 pm

Mine's being sorted out at the moment - I'll let you know what the mechanic says was the problem. Sounds similar problem to yours and it's beyond my basic skills...

Finnpaso · Post by **Finnpaso** » Sat Apr 29, 2006 7:22 pm

"FTD", HOW You check your sensors????

tell more about it! I comment more, after Your answer....

FDT · Post by **FDT** » Mon May 01, 2006 8:32 pm

Hi,

The sensors I checked with a multimeter and compared the readings with tables I found by a link on this site. The air sensor I took into the house and checked the resistance at room temp (outside it was around zero degree). The water senor with a cold and a hot engine. I also took the readings from the 35 pin connector. The air pressure was a little more difficult. I used telephonne cable (very thin wire) and place it in the connector and pluged the connector. So I could read the voltage with power on the system. Also compared the volt readings with table/formule I found. I as far as I know this were the right ways, but comment me if it wasn't. (I trust the duc specialist on the TPS).

greetings Frank

PS1 Rogero did you hear something from your mechanic?
PS2 I found something on the mailinglist -title "problem (fixed)"- about synchroning the ignition or coils?. What does/is it exactly. The problem descriped look very much the same.

Finnpaso · Post by **Finnpaso** » Tue May 02, 2006 2:45 pm

I think, You went right with sensors, but are You sure, that dealer check right way that TPS ??? It would be good to test anyway those sensors with that ECU tester(that blinking LED tester), or with Ducati Mathensis tester to be sure. You can find connector close to ECU. Have You checked valve clearences??? If clearances are not right, it causes also very poor running. I mean now exhaust upper clearance/closing) Compression test can show, if exhaust valves leak, what makes very poor running, what happened to me, when too bad quality valve seat material.

Rogero · Post by **Rogero** » Wed May 03, 2006 6:22 pm

Now take this as I give it but my mechanic increased the mixture by 3% to make it richer and it's now running fine.....

But how is the question?

FDT · Post by **FDT** » Wed May 03, 2006 9:43 pm

Rogero,

What was your fuel consumption?
And what is it after the change?

The effect of too rich mixture or too poor mixture look a little bit the same.
Too poor can be caused by leakage between cilinder and filter.

greetings and succes as the wetter is getting better at least in NL

Frank

Ps I will try to make time for a visit at the Duc dealer. To speak a mechanic I needed to do it in the week (not weekend)

Rogero · Post by **Rogero** » Fri May 05, 2006 5:47 pm

Can confirm I rode from Manchester to Liverpool then to Southport then Chester then Cardiff last weekend. Over 450 miles and only filled up twice. I'm getting a very healthy 45 mpg by my reckoning. But I am using Shell Optimax at over £1 per litre! OUCH.

FDT · Post by **FDT** » Fri Jul 07, 2006 7:04 pm

It have taken some time , but I did have an appointment with the duc store for checking the ignition system again.
They took about 2 hours for it and it really improved a lot.

The bike is good running in general
Also the fuel consumption 1L:15Km is a lot better.

Of course I think it can be better beacause it is still not compleet smooth between 3000 - 4000 RPM

Finnpaso you were right about checking the TPS although they had set it the first time. They re-adjusted it this time again. :screwy: (By the way before the last visit, I did try to measure the TPS it gave 175mV :umm: ).

Probably when I find time I will try to do the whole adjusting by myself once

.

Tip I put on new tyres Pirreli diablo strada & I like them a lot on this bike :lick:

All have fun driving

Ps Blackduc I think you have similair problem as I have or had.
You can also try to use K&N filters give more air and little poorer air fuel mixture It can just do the trick

cagiva905 · Post by **cagiva905** » Sat Jul 08, 2006 1:24 pm

Frank (and others),

The TPS reading is used by the ecu not only to calculate fueling, but also the igninition timing. There are tables in the memory similar to the fuel maps.

Actually, when the TPS calibration is off, the effect of the leaning or enriching of the fuel caused by this will be less than the effect it will have by offsetting the ignition curve. That's why it is so important to have the proper calibration of the TPS.

The reading your mechanic had of approx. 173 mV on the TPS is meaningless in itself. To calibrate it both butterfly valves should be closed and synchronous. The TPS should than be calibrated at 150 mV. After this the butterfly valves are set for idle running etc, toghether with the bypass screws. Because the valves will be more open than at calibration, the voltage will be higher as well. 173 mV could be a good value, but also a wrong one. This will be different for any bike.

Michiel

FDT · Post by **FDT** » Sat Jul 08, 2006 3:38 pm

Michiel,

I agree on what you write (I did read the article of the FIM). When I checked the TPS with the throttle valve(s) closed. At least the screw to set the idle running was complete turned loose. So I assume that the butterfly valves should be closed then (there was a smal tick hearable when the spring closed the valves)

When I have time I will try to do it the complete way as written in the FIM article.

greetings

Frank

Ps but I understand that it is possible to let a 907 run complete smooth trough all the revs?

cagiva905 · Post by **cagiva905** » Sat Jul 08, 2006 5:11 pm

What most people don't realise, is that there are 2 idle screws (or end stop screws) on the system. There is one on each throttle house. Both should be turned back completely. If the orientation of the 2 throttle housings is the same as on my Elefant (and I believ this is the situation), than one is located on the front left, the other one can be reached by removing the air box :screwy: . After the setup both screws should be set as a throttle stop, but I suggest to use only the more reachable one.....

In fact, by the nature of this system, setting TPS and synchronising the throttle valves (especially around idle with the bypass screws) need to be done all thogether. This because both housings and valves will never be completely identical, and there is only one TPS which is located on the right side housing.
Changeing sync slightly will effect both cylinders but the TPS is calibrated against only one. So this should be checked a few times during setup until a very fine balance is found.

And to answer your last question: Yes, a fuel injected Ducati such as the 907 is able, once setup properly, to run as smooth as a babies buttock from idle all through the rev range, even in gear.
Off course all mechanical parts like valves etc. must be in good condition for this as well.

My Elefant (mind you this is not even water cooled like the 907) used to be setup like this and ran like hell! I've been trying to reach this level of setup myself (my mechanic changed profession 3 years ago

so I started do learn it myself the hard way, step by step. I've got it 90% perfect now, so still a bit to go.. (needs a head overhaul)

Michiel

blakduc1 · Post by **blakduc1** » Thu Jul 13, 2006 1:49 pm

FDT and Cagiva905:

Yes this sounds like a similar problem and was discussed some a few days back. Seems that something is amiss for this system to be so complex to set correctly (I read the FIM write-up also). And it seems that it is far too common for the 907 to run raggedly and not always smooth. Other bikes seem to run pretty good still even when off a little. Is there some flawed component on these bikes that goes bad too easily? And why aren't there more certified Duc mechanics that understand this and know immediately how to correct it??

I do have the K &N air filter. I do have a clear fuel filter. I have replaced the voltage regulator. I have used Termigioni and F1 pipes. I have tried regular and high octane fuel both. I have used Euro chip and FIM chip. The problem is there either way, but regular runs better and that is what BCM recommended to me also. The problem does seem worse at higher operating temps and if the battery is weak at all. Could it be related also to voltage fluctuations?

Incidentally, these bikes seem to need the 42 tooth rear sprocket (which seems hard to find) to pull top end. Takes off from standing better also with 42 tooth.

Your input is appreciated.

DesmoDog · Post by **DesmoDog** » Thu Jul 13, 2006 3:41 pm

blakduc1 wrote:... And why aren't there more certified Duc mechanics that understand this and know immediately how to correct it??

Because it's a 15 year old bike??? I've never taken any of the certification clases, but I'd bet money they spend 99% of their time on current bikes. So basically you'd need to find someone who's been certified for 15 years.

Right wrong or indifferent, most Ducati shops don't give a rip about anything more than a few years old. Compound that with the fact most of the shops I know of now weren't even around when I bought my 907. And to top it off, the two I used to go to are both gone now.

Basically, the 907 has reached that age where many dealers have never seen one before...

Rogero · Post by **Rogero** » Sat Jul 15, 2006 6:11 pm

Regret to say that Desmo Dog is absolutely right. With 907's you'll be better dealing with a local mechanic than searching around for a Ducati specialist. I've been severly let down by the franchised specialist and spent a fortune.

My 907 has just been joined by a Triumph 955 Sprint, as I need something reliable and with a good supply of parts as touring on the 907 is becoming more of an adventure than a trip.

I'll never sell the 907 but she's going to be used less and more local from now on. I want to keep her going for as long as possible.

Rogero