Re: clean jets - Yeah, if your air filter is dirty (especially of it actually LOOKS dirty), that would absolutely affect the smooth fueling. As I said, my B12 is VERY sensitive to a dirty filter (I have some engine mods involved).
WHILE YOU'RE IN THERE.... (if you haven't put it back together yet), go through ALL the jet holes and channels you can get to... douche out everything. I learned the hard way to TAKE YOUR TIME and do a COMPLETE JOB while you can. Do you know how to check your float levels? No time like the present! You may find one of them is way off; it happens if it had gotten knocked...or maybe a previous mechanic didn't do it right. This could be a major reason for performance problems, and is absolutely worth checking while you're there. I believe flaot levels for all carbureted B12's is 13mm... but you should double-check that for your year. Investigate Youtube for the method, if you're not sure.
In terms of getting your carbs in and out smoothly-
- Lay the carb bank on top of the frame rails up top, (use a rag under them to keep from scratching the frame).. re-attach your throttle cables in that position. A good pair of needle-nose pliers will make getting the cables back on easier. Push the PULL cable down through the bank. leaving enough wire slack so you can manoever the ball end into it's hole.
(HINT- I do not run a PUSH cable... just the PULL. Take this suggestion at your own risk, as the PUSH cable is there for safety reasons... but I have been running just a PULL cable for years, on various bikes. You just have to make sure everything is clean and lubed, smooth action. Better to just stay with the factory push-pull set-up, if you're not sure).
- Spray a little silicone spray around the intake boots ONLY ON THE HEAD SIDE. That will help you plug the carb bank back in. Make sure your screws are loosened up enough on the clamps.
Then, manoever the bank down between the rails, and carefully wiggle them into line with the intake boots. Once in place, wiggle them around while shoving them in, one side at a time, keeping pressure on both sides. You will feel them CLUNK into place.
- Make sure your airbox is completely loose....take the two screws out that hold it to the frame.. and make sure you have as much wiggle-room around the wiring harnesses.
- Make sure you take the filter out of the airbox, so you can reach through the box to help align the airbox rubber boots onto the back of the carb mouths.
- Run a HAIR DRYER on HOT, across the airbox rubber boots for a minute before you try to plug them onto the back of the carbs. That will help a LOT. DO NOT spray silicone spray onto these boots (behind the carbs), as it will make it harder to get the airbox boots to stay in place.
- As you get one side of the airbox boots over the carb mouths, keep some pressure on the opposite side, with your knee, hand, or whatever you can... so the other side won't pop off. If your airbox is truly free of the harnesses and frame mount lugs, it will be a LOT easier.
- Reach through the airbox and feel for the rubber boots going around the carb mouths with your finger tips. These MUST all fit snugly. Use a long Phillips screwdriver to get to the clamp screws. The boots may pop off the other side as you get the one side clamped down. PATIENCE!
Once the boots are in place, then replace the airbox mounting screws in the back...then the air filter and clover.
- Only tighten up the intake (head) side air-boot clamps after the airbox is fully in place.
- Adjust your throttle cables carefully. Start with the cable adjusters (by the throttle) a bit loose, to give you adjustment room later.
Double check everything! Then, reconnect your fuel lines carefully, and make sure to turn the fuel valve to PRIME for a couple of minutes... watching out for gas running down onto the ground... which means you F'-d up somewhere...probably with your float mountings.
Hope this helps. PATIENCE! CLEANLINESS! THOROUGHNESS!
PS... I was riding my B12 yesterday and after a couple hours realized that MINE was sputtering just off idle. I know exactly what it is... a clogged pilot. So..I'll have to do the cleanout as well!
Fortunately, after 2 B12's (the current one with 130K miles), I've gotten good at it, and can get them in and out... 40 minutes in my shop... an hour, out on the road with my toolkit! Practice makes perfect.