Since you've already spent a lot of $$ shotgunning parts at it (including the CPS), are you ready to get away from the expensive and time consuming guesswork and start some basic diagnosis?
Please correct me if my description is inaccurate:
You park it when it starts to get cold out, but it's accessible in the garage and not on a battery tender, so you fire it up every month or so to charge the battery and warm it up. During the winter it gets harder and harder to start until now, when it just cranks over fine but will occasionally spit fire out of the intake or exhaust.
Yes?
I would do 3 things immediately:
1) Stop doing that. Get a tender and do NOT EVER start your Buell unless you RIDE your Buell. They have a very rich and very long cold start cycle. Starting it and idling for 10 minutes every month only exacerbates the fouling of the plugs, puts acid in the oil, doesn't charge the battery enough to matter, is hard on the stator and VR, annoys the neighbors, and is worse in every way than just leaving it alone so...
2) Remove and CLEAN the plugs with cleaner and air pressure. Even if they weren't fouled before, the repeated start attempts have fouled them, so they are fouled now.
3)
You have messed with the ECM* so now you HAVE to do a TPS re-set: Not doing it (or doing it incorrectly), WILL cause exactly the issue you are having.
http://buellmods.com/content/downloads/manuals/xbxulysses/2007_ulysses_manual.pdf (PAGE 1-49)
Do the
procedure. Don't just smash the reset button.
You don't need the digital technician, you can do it with your android phone and the free program ECMDroid (GooglePlay store) and a bluetooth dongle (I like the one I got from Rev-Mo.com), or ECMSpy with a wire and a laptop, or TunerPRO. AND remove and look at your ECM. The Uly's with the low seat had an issue putting weight on them and cracking the box. Put a ball of Play-Doh on the box, install the seat and sit to see if the clay gets squished. There is a bracket available to move it if its an issue.
For bonus points, and even though a botched TPS re-set would cause exactly this issue, your 'shop got it running but not idling' comment got me thinking that 1/2 the coil might be bad. Buy a spark tester
https://www.amazon.com/Ignition-Dia...ocphy=9031012&hvtargid=pla-470014912016&psc=1 and check the
plug end of the wires while cranking. It is 2 coils in one so you need to check both sides. You should see a rhythmic light pulse. No light or an intermittent/stuttering light and you'll be looking in the direction of a bad coil/bad plug wires or bad primary wiring. If there is an issue, check the coil inputs with a 12v test light. Put the 12V test light (one at a time) on the wires that are on the outsides of the 3 pin plug that is on the coil. Should see the same rhythmic light pulse while cranking.
TL;DR
I'm betting cold starts have fouled the plugs and a TPS re-set was never done correctly.
