This is to hopefully help others that have had trouble in finding answers to at least this combination of performance upgrades on a 996 or? This pertains to a 2000 - 996. Long frustrating story but will try to keep it short. Yeah right!!!
In stock condition it had the normal off idle bogging (overly rich) condition but never noticed the 3500rpm hesitation noted by others. Installing the Termignoni’s did help the bogging problem but the bike just didn’t run to its potential so the Ultimap UM222 was the next step. Finding one was a story in itself, but fast forward. Not being familiar with this bike I decided it was best to take it to the dealer and let them install it and dial it in just be done with it. Well.. Lots of $$$$$$$ later, it wasn’t right and now had what I determined was a lean miss condition between 4000 - 5000 rpm, also looking inside the left muffler it was white like extreme heat had been cooking the soot off - and it was -- too hot and time to stop riding it before damage occurred.
Living over 250 miles from the dealer became an issue, numerous calls were not helpful as answers were non existent from them even with educated input to the problem. Searching the web was my last resort so between many emails, blogs, etc. there were lots of opinions, facts, misinformation and so on. Bottom line: It was time cut my losses, dust off the tools and fix it myself. My only reservation was if the dealer had changed the mapping on the chip, because if they had, I was stuck as finding this software/equip was impossible. I lucked out.
The miss was in fact a lean miss. Checking the CO to start found the Ft Cyl was set at about 1% to 1.5% CO, Rear 1.5% to 1.9% CO and the throttle bodies were out of sync. by one line on the mercury stick. The front By-Pass screw was out just shy of 1 turn and the rear was about 1.75 turns out. Also the trimmer in the computer was neutral (center position (2.5v).
Starting from scratch, following the manual step by step, TPS, Bypass screws seated, Fired up, set Balance and this is where I failed the first time. I followed the manual attempting to bring the idle up to 1100 rpm with the By-Pass screws. NOT gonna happen. I had them turned out to where they no longer had any effect still not arriving at the desired 1100 rpm, which also affected the mixture/balance. I “cheated” using the TB stop screw to achieve the 1100rpm. At least I thought I was cheating thinking I was going to screw up the TBP voltage, throw off the fuel mapping, etc. Not the case (I found out later) finding this info in a paper written that I would love to give credit to but can’t find it right now but stated using the Stop screw was the correct method as the By-Pass screws were only to be used to adjust mixture conditions between the cylinders and should only be out no more then roughly ½ a turn. Before wrapping thing up, Ft cyl was 1.6% CO, Rear 1.5% CO, trimmer 1/8 turn rich. Test ride showed no improvement.
Second attempt: Knowing the TPS was set, seated the By-Pass screws, brought idle to 1100rpm. This brought the Ft cyl to 3.5%CO. The rear I was having trouble with (high 4-5CO% but even more so the HC (hydrocarbons) were telling me I had a miss @ 7-9PPM but bringing the CO% lower also lowered the HC, to a point, if a miss HC will usually go the other way) but finally got it to 3.2% CO idle @ 180 degree F plus. It was a chasing game. By-Pass screws will change the balance and so on. Final setting: Ft Cyl 2.5% CO, Rear 3% CO. Rear By-Pass screw out ½ turn, Ft seated. This “TRANSFORMED” the bike. OMG. It sounds different, and runs very strong, like never before. Wheelies in second gear with little to no prompting.
The trouble I was having with the rear cylinder mixture I think might be a partially plugged injector the way it was acting, because it would keep radically changing on me. Spraying good then dribbling, then spraying and so on. Using plenty of injector cleaner now if this is the case.
What really amazed me was how much the Throttle Bodies and By-Pass screws affect the mixture and running. The trim screw was returned to the middle setting (2.5 Volts) as received from the dealer. The Throttle Bodies were the key and the dealer (as far as I’m aware) NEVER touched the balance, only the TPS. The balance was out along with the mixture and by-pass screws causing the lean miss. I realize for emissions the manual calls out 1% CO, but for performance they also call out 3-4% CO and engine damage can/will be caused running too lean. Grant you there are other things like Ignition, Burnt Valves and so on that can cause a miss, and I’m not implying the miss you may have is a lean condition.
One more thing: I noticed the left muffler always ran hotter. Everyone I encountered says the same with everyone’s opinion (even the dealers) seeming to be the rear cylinder runs hotter. When I was trying to determine the miss I was having thinking the rear cylinder was running lean looking inside the left muffler and feeling the difference in heat after a ride between the 2 mufflers, so I too fell into this opinion, however it never made total sense to me because of the fact it is a water cooled engine, and the pipes are most likely of equal length. During warm-up, the left muffler exhaust gasses are ALWAYS hot and the right cold with NO air moving over the front cylinder, and I don‘t believe the front cylinder being surrounded by heat exchangers gives it much advantage to cooling. Checking the pipe temp out of both heads revealed about equal temps. Where the change came was “after” the pre-mufflers, the left pipe becomes hotter. So paying close attention to this I came to the conclusion the blending of the gasses is not equal where they blend together and balance the pulses at the base of the pre-mufflers. So I think the majority of exhaust gasses travel through the left muffler thus becoming hotter then the right. Check it out for yourself.
So, in conclusion: All this hassle was because the dealer failed to do the basics: set the Throttle Body Bal and By-Pass screws accordingly. I know where I’ll never go again.
Hope this long drawn out story will help others. Since purchasing this bike it has been nothing but problems. Some minor in nature (but finding info was like pulling teeth). The first being previous owner caused. I also posted the trouble and fix for
porosity in the rear cylinder head inside the spark plug bore I had, something that Ducati of NA wouldn’t acknowledge ever having issues with. Guy at MBP in Canada (valve retaining system) called me as he had seen this and gave me the fix. Thank you Guy, you’re one in a million.
Mind you, this bike was stated to have only 229 miles on it. All indications were this was true. It now has 2300 miles on it. NOW it’s running so strong it’s hard to imigine selling it, something I came soooo close to doing may times.
I’m finally smiling!!!!!!!!!!! Thanks to all that gave their input during all this, at this site and others.
Happy New Year!!!!
Oil Filling up in Spark Plug Bore - Rear Cylinder
Effort = Results
Thanks for the info.
Linear Mode
