Are you sober yet ruth?

And i'd like to lodge a protest. Not sure why yet, but i'll think of something :frog:

I should have my answer to Q1 ready at lunch time... i have to go make a couple of references in the company library just to make sure some facts are right. But be ready, cos i think the real cause of this "stutter" will suprise most people, even the very knowledgable shazaam! :o

I'm as sober as I need to be to drive a desk, mate! :P

The Library :o:o:o

If you set the standard this high you'll be very hard to beat, Nick!

However, Shazaam is already streets ahead of you as at 9.30 this morning. Still, day 1 and I'm sure there'll be dozens of toe curlingly technical posts to plough through by 28th February.

Hoping to get a few as yet unexposed nerds playing along too. ;):D:devil:

Well ok ruth, so as not to dissappoint you further, i've put my career on the line and scived off work for 15 mins to complete my answer. What was the question again?? Oh, I remember...

"Why do 996 bips seem to develop a stumble/missfire,when getting back on the gas after they have been cruising on low revs /high gears for a while?"

The scientific answer:

Since I work in the petrochemical engineering design and consultancy business, this isn't too difficult a question, but let's try to explain it in layman's terms...

This problem(?) is such a finely balanced chemical reaction that it only tends to affect the more highly tuned engines which demand nothing short of perfection. So and if your bike is doing it then you've good reason to be proud of your stead!

It's actually not "missing a beat" initially, it's to do with the phenomenon of the suns rays drawing streams of heavy-metal gasses as they pass through the atmosphere of the planet Mercury (have you noticed it doesn't happen at night?).

This metallic rich air, if drawn into the cylinders in large enough quantities (like when opening the throttle quickly), causes a heavier air content in a single combustion which changes the atomic structure of the metalic atoms and acts like a magnet to oxygen drawing most, if not all, of the oxygen from the airbox in one go. When the airbox "recharges" with fresh air then all is fine again and the combustion cylces can return to their rythm of the steady cruise.

Now here's the twist...
It's probably more likely to happen with mav's bike because of the lack of salt in the air where he lives in the midlands; since the salty sea air on the coast, when mixing with the metallic gasses, actually forms a chemical imbalance at several different temperature ranges of the inlet tracts preventing too much oxygen being affected by this magnetic pull - it works in a similar sort of way to reversing the poles on a magnet.

Geographic location obviously depends on the wind direction, but living on the south coast means it happens with my bike very rarely due to the common south-westerly winds bringing in the sea air.

nb
:D


[Edited on 1-2-2005 by NBs996]

Wow, very clear and totally explanatory. Well done Nick.

I'm going to have to keep a running total of who's ahead at the end of each day! :eureka:

You left out the bit about standing on one leg!

:lol:

Actually, my 996 bip had the stutter as well and it is down to the twin injectors. Neil Spalding, as part of his 996 bip racer "Grunter" spec does the single injector mod with the FIM chip. I had Neil's full monty done and the grunter spec at the same time and my bike is fine now.

In fact, it's more than fine. I would suggest it goes harder than most 996's without headwork etc. Check out what Neil does in the Grunter here

Just had U2U from Dickieducati to say he agrees to help judge but was a bit confused by the competition.

In case there are others out there who don't understand, this is how it's supposed to work:

1. Post a question, any question, as easy or difficult to answer as you like but BIKE related. (Ducati, obviously)

2. Wait for replies to be posted.

3. At the end of the month, the prize will go to the person who has displayed the greatest depth of knowledge but who has also made the greatest effort to answer as many of the questions as possible. So to win you really have to be logging on to the board regularly, if not 28 days in a row.

Hope that's a bit clearer now.


:sing::sing::bouncy::bouncy::bouncy:

This is a very good point NBS996, but I think Madmav should check the airbox seal with the tank, I believe a methane buildup behind the tank which is leaking into the airbox causing the rich running when the throttle is opened. If Mav can't fix the seal then a change of diet maybe the best cure. Alternatively you could weaken the fuel mixture & take advantage of the methane.

I particularly like this quote from Neil in the article I listed above on the Grunter spec.


I go back and read that every now and then when I'm thinking of selling mine and getting a 998R. Then I remember how much money I've spent on the 996 ...... then I go and lay down ...

Well, here's an alternative not-quite-by-the rules-that-were-described-but-that-has-never-stopped-me-before answer ...

Actually what you are describing is quite common to many bikes, and it's usually associated with cruising at a throttle opening and rev range that is just 'below' a lean portion of the engine's setup - so - when you open the throttle, the mixture goes lean and the engine stumbles. On a carbed bike you might raise the needle, on an injected bike you need to go see Sigma :burn:

Why when you dial a wrong number is it never engaged?

This question of course only relates to ringing Ducati dealers so as to qualify for Ruths guidelines.:D