If you are chasing carb jet problems because the bikes have been sitting, you probably do have some gummy carbs. But it may not require a carb tear down. If it's not too bad, a few tanks of B12, Techron, Seafoam, etc. may pretty well clean them out.
BUT, track down and fix your vacuum leaks first! Many of the symptoms are the same and your carb problem may not be as bad as it seems.
Also, vacuum leaks will affect carb balance and idle speed, so if you adjust either of these without finding and correcting the leaks, your adjustments still won't be correct.
Once the vac leaks are taken care of, you'll know better how serious is your carb problem.
I've got a '98 Standard that I pretty much let sit for a couple of years. Solvent in the gas cleaned up the pilot (slow) jets (which weren't bad, they're #38s) But I still had to track down some backfires,
After making sure my exhaust header bolts were all tight, I started looking for vacuum leaks and found them in the vacuum caps and lines.
Also, some of the bands around the intake tubes had loosened as well.
Correcting all this brought the bike back to smooth running.
Finding what sucks:On the back side of each of the six chrome intake tubes is a nipple:
If your bike has been de-smogged, you'll have a vacuum cap on five of them and a vacuum line leading to the petcock on the sixth. If your bike still has its smog gear, you'll have three with vac lines and three with caps.
Theses are also the nipples you connect your gauge lines to when balancing the carbs.
The vacuum caps and lines will eventually break down because they are exposed to fuel/air mixture and the fuel attacks the rubber components. The leak usually occurs on the bottom side, hidden from casual inspection. You have to pull them off and examine them closely.
This one looks pretty good, right?
It's not, but you couldn't tell with it on the nipple.
Beware replacing the vacuum caps with cheap stuff from an auto parts store and ditto for vacuum lines. This is the stuff to use for vacuum lines
http://www.valkyrieforum.com/bbs/index.php/topic,72242.0.htmlI now make my own vacuum caps with short pieces of this silicone hose, black RTV adhesive/sealant and #8 x 1/2 machine screws. Cut the lengths, pookie one end with sealant, insert the screw and let cure. They grip well and don't need clamps. (Note that I did not have these on the bike. The leakers I found were Viton B, installed in 2011. I have the home-made ones on now.)
Here's one of my home-made caps. I make a dozen or so at a time and give them away at wrench parties or the monthly meetings.
If you want to buy your vacuum caps instead, I recommend these:
http://redeye.ecrater.com/p/3301919/three-vacuum-caps-honda-valkyrieWhile you're replacing caps and lines, take an 8mm wrench and check the nipples for tightness. They can loosen. Some folks replace the nipples entirely with a short bolt of the same thread. This eliminates the need for vacuum caps entirely. If you do this, hang on to the nipples because you will need to reinstall them if you ever sync your carbs.
Another source of vac leaks is the bands that hold the carbs to the chrome intake tubes, and the carbs to the feed tubes from the airbox. There are three sets of these, so 18 in total. They are all tightened with 8mm bolts or Philips (JIS) screws on a steel band, similar to a radiator hose clamp.
The ones that connect the carbs to the chrome intake tubes are easy because they are exposed.
There's another set immediately above these. You have to remove the chrome valance that covers the enrichener (choke) cables to see them.
The third set, which is just above the carbs, can be reached by lifting the tank an inch or so.
They all need to be tight to eliminate leaks at those spots.
The final common source of vac leaks is at the base of the chrome intake tubes. Each of these is held in place by the connecting band at the top and with a pair of bolts at the base.
Underneath the tubes is an o-ring.
Like the vac caps and lines, these deteriorate over time. Usually, you'll know you have a problem because there will be coffee colored stains on the top of the block around the base of the intake tubes. This goo (technically "mung") is fuel residue, the same stuff that collects in the vac caps and tubes and rots them.
If you see stains, get some of these:
http://redeye.ecrater.com/p/2064055/intake-o-ring-kit-viton-gf, and replace the old ones (it's easy.) No stains? Check the base bolts are tight and roll on.
Hopefully this is helpful info and will save a few of you from doing fruitless carb rebuilds that still leave you scratching your heads over rough idles and backfires.
