Guest motor72 Posted June 26, 2004 Share Posted June 26, 2004 Just received and installed the mistral aluminum cans. Excellent sound but the bike now has a flat spot just off idle. It runs fine everywhere else. The only other mod is a drilled airbox lid. My question is can the fuel injection be tweaked by a dealer enough to cure this? Link to comment Share on other sites More sharing options...
Mike Stewart Posted June 26, 2004 Share Posted June 26, 2004 Here we go again! The cheapest and easiest way to compensate the air fuel mixture is by installing a Powercommander (PCIII). The dealer can tweak you stock ECM but, how many dealers have a dyno to do it correctly? My 03 Rosso ran very bad after installing the Mistrals. The PCIII enabled me to correct the lean areas to make a very responsive bike. Mike Link to comment Share on other sites More sharing options...
helicopterjim R.I.P. Posted June 26, 2004 Share Posted June 26, 2004 PC III is adefinite must but you may also appreceiate the benefites of a Mistral or Stucchi crossover. The Mistral boosts midrange like you wouldn't belieive and the Stucchi is great for top end. Fast by Ferracci has some great downloads for the PC III for these combinations. Enjoy the sound and the power. Link to comment Share on other sites More sharing options...
docc Posted June 27, 2004 Share Posted June 27, 2004 The cheapest and easiest way to compensate the air fuel mixture is by installing a Powercommander (PCIII). Weeell . . . I'm thinking the "cheapest and easiest" would be to adjust the valves .006/.008 or more, perfectly balance the throttle bodies and tweak the TPS a tad. I'm sure it's not the 'optimum' set-up but definately 'cheap and easy' ( like me). Link to comment Share on other sites More sharing options...
helicopterjim R.I.P. Posted June 27, 2004 Share Posted June 27, 2004 (Mike Stewart @ 26 June 2004, 03:44) The cheapest and easiest way to compensate the air fuel mixture is by installing a Powercommander (PCIII). Spend the money or be happy with the flat spot. Link to comment Share on other sites More sharing options...
docc Posted June 27, 2004 Share Posted June 27, 2004 I wish we had a nearby dyno center. I'd be more confident in spending the $$$ and getting the thing right the first time. Also there have been more than a couple reports of problems after adding the device. With my bike running pretty decent I don't know if I want to risk another source of reliabilty issues. Link to comment Share on other sites More sharing options...
helicopterjim R.I.P. Posted June 27, 2004 Share Posted June 27, 2004 It is true that some problems may occur with the PC III but there are several user submitted profiles on the Power Commander website that usually fix them. A dyno would be helpful but it is only required if you go farther and add stuff like headwork or raised compression. I wish all Moto Guzzi dealers had the equipment the Aprilia dealers have access to. It will reprogram the stock ECU box and saves adding extra's like the PC III. Link to comment Share on other sites More sharing options...
docc Posted June 27, 2004 Share Posted June 27, 2004 Is that just the hand held software interface device in conjuction with a gas analyzer? Link to comment Share on other sites More sharing options...
helicopterjim R.I.P. Posted June 27, 2004 Share Posted June 27, 2004 No - that is available to all Moto Guzzi dealers. The unit I saw is similar to the system Fuelinjectedmoto of Australia uses. It will 'reburn' the memory of the module to a complete new curve. It is available to 'some ' Aprilia dealers. I presume it would work best with a dyno and a gas analyser. I saw it at a Guzzi/Aprilia dealer in Sydney, Australia and it was mostly used to convert any bikes that were shipped with California specs (ie very lean midrange and corresponding flat spot). The Australians conform to the European specs and get very upset with the Cal spec bikes. It is also used to set up the bike when certain Aprilia factory performance parts are installed. It is also used for Moto Guzzi problems but the dealer said they don't use it as much. They don't have many problems with the Guzzi's when set to European specs. Link to comment Share on other sites More sharing options...
docc Posted June 27, 2004 Share Posted June 27, 2004 I wonder if the US bikes have a deeper flat spot than the Euro or Canadian bikes? Different part numbers for the ECU maybe? Link to comment Share on other sites More sharing options...
helicopterjim R.I.P. Posted June 27, 2004 Share Posted June 27, 2004 All Canadian bikes come with California specs as do all US bikes I believe. The flat spot on my Rosso Mandello was so annoying (4000 to 5000 rpm) that I ahd to change something before I had 5000 km on the bike. I couldn't ride in in that rpm range at all. Now 4500 to 5000 rpm is my favourite range because it all starts happening there. I don't think the European bikes have much of a flat spot if any. Link to comment Share on other sites More sharing options...
Mike Stewart Posted June 27, 2004 Share Posted June 27, 2004 I wish we had a nearby dyno center. I'd be more confident in spending the $$$ and getting the thing right the first time. Also there have been more than a couple reports of problems after adding the device. With my bike running pretty decent I don't know if I want to risk another source of reliabilty issues. Docc, I have heard of a few PCIII maps that still needed to be tweaked after the bike was dynoed at a Powercommander facility. Don't get me wrong, the bike will be very close, but sometimes, things just do not show up on the dyno. Let's take the lean backfire that the 03 bikes produce when the exhaust is changed. The bike on the dyno will show that everything is fine but when the bike is ridden, at times there will be a backfire at about 2500 rpm. when comming to a stop. Well by making the lower throttle opening richer, the problem is eliminated. I have also heard of surging or slight flat spots after having the map made. This could be caused by just a slight leaness in the effected rpm range. What could be happening is that the correct air fuel ratio was picked but your bike may need to be richer than the optimum for this condition. Remember there is a fine line between performance and fuel mileage. Most of the PCIII returned to Dynojet are found to have had the harness pinched or chaffed by incorrect routing of the harness. There for it is very important to route the harness away from any sharp edge or anything that could pinch the harness such as a side cover or seat. There are most likely a small amount of PCIII that are defective, but you will get this with any type of electronics. Even in automobiles you will see failures in electronics. Just think about all the vibrations, heat and temperture changes that happen day to day on your bike. Just having your bike sit in the sun for a few hours could raise the temperture up pretty high under the seat. I have over 30,000 miles on my PCIII and have nothing but good to say about the product. For every change I do to my bike, it is so easy with the stroke of the keyboard change the air fuel ratio of the bike at any rpm range or throttle opening. Where else can you go online and download a map from across the Country, download it into your computor and do a comparison to your existing map. There have been many times when I have changed the map in my bike to compensate for a ping or richness at idle. Just plug the PCIII into your lap top and add or subtract in the rpm range and throttle opening that the problem occures. No screwdrivers or hammers needed. I am not saying this is the only way to adjust the fuel mixture of the bike. But to me, it is the cheapest and easiest way to do it. Mike Link to comment Share on other sites More sharing options...
Guest slowpoke Posted June 28, 2004 Share Posted June 28, 2004 Mike, you said that the backfiring at approximately 2500 rpm's is caused by a lean mixture. That is true and much easier to correct on a carburetted bike but I'm puzzled by the buttons on the PC111. I had my bike set up on a dyno and they probably did not detect the backfiring however, I opened up the airbox and installed a K & N filter after the dyno session so maybe that is what leaned it up. Now going back to my other question. If one re-maps using the computer what are the buttons for on the PC111? If I could just push the low button and richen it up akin to turning the richness/mixture screw on a carburetter all that offensive backfiring would be over. This is on my Cal EV and not my V11 which seems to run fine with map that is on it. Can you shed some light on this phenomenon? Link to comment Share on other sites More sharing options...
al_roethlisberger Posted June 28, 2004 Share Posted June 28, 2004 A lot of Moto Guzzi dealers(such as ours in San Mateo) do have the system to reprogram the ECU(at least the fuel/air curve anyway, not sure about ignition) but few have the additional equipment such as a Dyno, or experience(in North America anyway ) to do much more than get the CO correct through the use of a tail-end gas analyzer. With that in mind, most can only get the bike to "run OK" and within spec after various modifications, as opposed to really tuning it optimally for your goals. This is why most owners in North America have opted to use the PCIII in conjunction with the ECU, since the PCIII Certified Dyno Centers are much more plentiful than a shop that can tune the ECU. Apparently, elsewhere... especially in Europe, there however are instead quite a few shops that have extensive experience in reprogramming the 15M, so the requirement for the PCIII may not be as popular But in my experience, the PCIII is a good alternative if one cannot find a shop with said experience, or equipment. al Link to comment Share on other sites More sharing options...
helicopterjim R.I.P. Posted June 28, 2004 Share Posted June 28, 2004 Dear Slowpoke Don't mess with the buttons on the PC III. They are only temporary. If you still have problems after a dyno session than you should only adjust the graph they gave you and only in small increments. I f you haven't been on the dyno then either go on one or find a graph that matches your set-up exactly. Good luck mate!! Link to comment Share on other sites More sharing options...
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