Two questions-CO &... : LUSENET : MV Agusta F4 : One Thread

I find the bike with pipes and Eprom practically unridable from 2-4K. Someone mentioned raising the CO level. How is that done? I thought the chip controlled that?

Second, is there no search function here?

-- Willard Fossy (, May 11, 2003


Which engine do you have and which exhaust headers and slip-ons are you using?

-- dm (, May 11, 2003.

U.S. 02, with Ferracci chip and pipe. (Sile)

Again, how is the CO adjusted?

-- Will (, May 11, 2003.

With non-MV or non-MV-SP parts, it may require the services of a competent tuner. That's the route I'd take since it's doubtful anyone has actually mapped all the possibilities. A PowerCommander might even be needed to get it set-up perfectly. OK, on to your questions.... First off, for me anyway, 2-4k rpm is just a stage I pass through momentarily rather than "ride" at. Further, tuning in that range may prove difficult as most dyno work begins around 4k rpm. A sprocket change might be more what you are looking for if it's off the line performance you are after. Still, if the CO is off, it's off and needs be adjusted. As to the "how" part of the your CO question , you'll need to get back into the box where the chip is located as follows: 1) bike needs to be warmed up and key off; 2) remove FI box under the seat (four bolts) and ground it properly; remove rubber cap; 3) pull out your trusty CO measuring equipment - red cable to positive battery pole, black cable to ground; 4) pull out the CO% screw on the rear section of the manifold if stock (note: this hole may never have been drilled out, more later) - center single-pipe section if SPR manifold - and insert CO measuring probe (I believe this is the same size as used on 996) - or, use a tail pipe probe if you don't have the right equipment; 5) check everything over again, start engine, let it get back up to temp (fans should click on) and read the CO%; 6) make changes as needed to the trimmer tab inside the FI box (next to the eprom itself) using the proper tool until you get the CO% specified; 6) that's "it", put everything back together and add a bit of silicon sealent around the rubber cap. My opinion...if you don't have the right equipment or are in doubt about how to do this, you could do much more harm than good - ala damage the FI unit. If this is the case and/or you are installing equipment that isn't designed and tested to your "exact" motor, headers, slip-ons, you'd be best off going to a qualified tuner with a dyno. Accent on the "qualified" part. Just my 2-cents worth. Lastly, the search function here IS weak - I just use the "Find" under the "Edit" tab on my browser. Perhaps there's a better way? Good luck and let us know everything works out. dm

-- dm (, May 11, 2003.

The trick is getting the CO setting and the carbs sychronized and set up properly.

The CO settings need to be approximately 3.6% +/-0.1. This should be done by your dealer. The throttle bodies need to be synchronized properly so that the bike will run properly as well.

The EPROMs for the most part will work really well if the CO and the throttle bodies are synchronized properly.

Another thing that you will need to do is make sure that there is a little bit of slack on your throttle cable to give you a better initial feel for the throttle.

If all of these things are set up properly you will find that the bike will run smoother and make a lot more power.

-- (, May 11, 2003.

Thanks very much! That is what I was looking for. Bravo.

It's not performance I'm after at that RPM> When I say unridable, I mean unridable! LOL. It stumbles and falls all over itself at steady throttle. Any increase and it smooths out. If it were a carbed bike I would fiddle with the pilot jet I beleive.

There is no way to avoid it, 55mph=4K...I have to get through traffic before I can ride...unfortunately I don't live in the Matrix but the real world. :)

-- Will (, May 12, 2003.

It sounds like the dealer didn't do the pre-sale set up properly as the C0 adjustment is definitely off.

I bought a used 2000 model two years ago from the first owner. The dealer didn't properly set up the C0 either. The results were stalling, backfiring, very poor response from 3K to 6K rpm and extreme response after 6K. The MV is very sensitive to its CO setting.

A CO adjustment under warranty will get you up and running. :)

-- Allan Gibbs (Phoenix, AZ) (, May 12, 2003.

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