I use thiskind: http://pdfkatalog1.louis.de/cgi-bin/det ... ?page=0891 meters and function very well....

vacuum balance shouldn't have too much to do with the chip.

spark timing will affect cylinder scavenging [de-pressurization after combustion] - but the exhaust stroke takes care of most of this...

valve timing and cam will affect all cycles for the four stroke...this is unlikely to be poorly managed with a Ducati; the timing and cam should always give almost race-tuned optimum...

if there is significant vacuum balance [intake] difference between cylinders it could indicate a bad valve. I know there is some rear cylinder offset / comphensation written into some Ducati chips...my understanding is this is fuel related [richer to rear] to make the rear run a bit cooler. I'm unsure how this is handled in various chip types...maybe you could ask if you get a new chip?

the throttle bodies and butterflys are obviously not exactly "precision" made - so unless the bike has had some serious flow-bench work it's not likely to give spot-on results thru the rev range [and associated throttle positions]; the reason I choose (say) 4,000 RPM is that's where I do most riding..so for me it made sense to get the throttle settings balanced around this point (although ovbiously the settings are not made under load).

I'd be interested to know if you've left the ciggie butt in since the TPS re-set...

I've posted how to make a quite simply and cheap balancer in the 750 F.A.Q. if you mean to build it yourself

And furthermore , for tuning 40mm Helldortos on my 82 900ss ,, Start with gauges calibrated, or as near as you can see (Not far these days , unless its some young honey) Air lines damped with the small taps sold for Drip irrigation lines,( Are these OK Laddie?) screw in or out till fluctuation minimised, synch over a few rev ranges.....probably no good on a track bike but works well on my old heap. Cables to carbs have to pull reasonably equal first.

Would not reccomend this technique to a fanatic............Marty

I finally broke down and brought the bike to Wagner Motorsport for service. The found the cam timing sensor was out of spec and the connector on the barometric pressure sensor was loose. He removed a shim from behind the sensor and safety wired the connector and the problem went away. Laddie, it still has the ciggie butt in the line but I don't know if it would have a problem now without it.

Shelboss,

easy test...just take off the airbox to sensor tube and pull out the ciggie butt...

I haven't done this for fear of being struck down with the dreaded lurgie.

i recently had a plug lead die on me AND the ECU plug gave some problems, too.
I had some doubts if the ciggie butt was failing me.

I worked out the ECU plug because the bike would miss often when I hit a bump.
Not being adverse to "tapping" things I took off the seat and "voila" the bike would miss or stop altogether if I tapped the ECU. A quick spray with WD40 and problem solved.

The plug lead was a simple open circuit test. A measly $ 5.00 for a replacement lead at SuperCheap auto. I was so happy it was that cheap I bout 2 and a new torque wrench and some 3/8" drive allen key bits...

Laddie, I tried the gig butt and it seems to work for me too...

dp