Sports: [DucatiST] " Carburetion" flat spot

Dave,

When I purchase my used 2001 ST2 in 2005 it had a really bad flat spot around 4000 rpm. There are two Duc dealerships in the Seattle area. I asked the the dealer I bought the bike from to replace the chip but, told me they could take care of the flat spot with a tune up, which turned out to be incorrect. After about two weeks of lame excuses, they told me the chip was unavailable. I went to the other Duc dealership and they had a new Ducati Performance chip for $75 within a week which plugged right into the ECU under the seat within a couple of minutes.

Wow, WHAT A TRANSFORMATION!

The flat spot was eliminated and the bike pulls smooth and strong all the way through the power band. My thought is that the bikes are leaned out from the factory to pass EPA standards for import. For $75, it is no doubt the best value of any of the mods I've done on the bike, and I would strongly suggest it for a stock ST2.

Enjoy the new bike,

Marty Nelson

2001 ST2

Seattle

On Aug 15, 2011, at 11:16 AM, David Gooch wrote:

2002 ST2 62,000 km

Yes, I know that the ST is fuel injected. It just seems right to say that it
is not "carbureting" properly than to say that it is not "fuel injecting"
properly. It just doesn't flow as well!

As you will know from the "gear whine" posts, this is a new to me bike this
year. I have put about 5000 km on it so far without any major trouble and
the previous owner is deceased and not answering questions.

One of the things that came out of my mountain riding this past weekend is
that there is a big flat spot in the "carburetion" between about 3700 and
4100 rpm. The bike will actually stutter if you try to give it throttle off
the bottom at that rpm. It will pull through that range, but it is
definitely non-linear. BTW the bike has the stock air filter and exhaust. I
am assuming that the ECU has a stock chip, but I know from the markings on
the case of the ECU (ST2 Good - in yellow paint) that was taken from a bike
in a scrap yard.

It this normal for this bike in this state of tune? Do they all do this and
if so, what can be done to reduce the problem.

I also need to say, that the bike still needs a full service as that may
well be the cause. I need to check the valves, zero the TPS, adjust the O2
pot, install new plugs and balance the throttle bodies before I dig into
this particular issue. How will I know if the chip in the ECU is the stock
ship? Are there any markings?

I am going to do the obvious things first, before digging deeper into the
cause, but I thought that I would ask for some guidance.

Thanks again!

Dave G.
aka The Goochman