OK, here's what I found in the carbs

[11Rider]

The carbs are very clean, but I'm trying tor track down the idle to 3k rprm problem. Most here figured it would be something with the pilot jets. My mains are 137.5 -all of them. The pilots are 42.5. All the side holes are perfectly clean, but one you can see all the way through, three you cannot because the little hole at the end is plugged. Could that be enough to cause a low rpm problem? If not, should I go bigger on the pilots?
BTW, am I correct that the gas goes into the main jet, then into the needle jet, and then some of that goes through the pilot jet? It looks like it has to go through the main to get to the needle and my pilot jets are all covered by screws.
I'm getting a pretty good idea of how these things work thanks to all of you. Please help me to understand this part. Thank you.

[Incubus]

If when you talk about seeing light through one and not through three you are talking about your idle jets... You need to be able to see light through all your jets. If you can't then you need to clean them again. Going to larger idle jets before you try to clean the ones you have is really not a good diagnostic route. Clean them until you can see light and try the carbs again.

Low range problems are your idle jets, so you are on the right path.

While you have your idle jets out, spray some carb cleaner into the tunnel you pulled them out of. The cleaner should bubble up through three tiny holes in the carb throat right about where the edge of the butterfly contacts the carb throat. This is the rest of your slow speed circuit. If you don't get carb cleaner bubbling up through all three, try letting the carb cleaner sit in the circuit for a while and then blowing it out with compressed air. If that circuit is not clear then you slow jets have no passage to feed fuel to the cylinders and you will have issues with your idle and your lower range.

Patrick

[11Rider]

Thank you Incubus. I believe the term "idle jets" and "pilot jets" are interchangeable so I would assume I may have found the problem with three plugged jets.

Also, I was reading in Blaines writeup that not all carbs have a screw covering the pilot jets. Could I leave the screw out to enhance (richen) the pilot circuit? I'm going to K&N pods soon

Thanks very much!

[Incubus]

Well that certainly would richen your idle circuit, but it might be a bit more than you want. You have the early carbs that are designed to have that tunnel plugged. The slow jets are fed through the main jets. Later XS carbs have direct feed to the slow jets with that tunnel unplugged, but the main jets are much smaller. Early carbs also have a small hole in the side of the main jet tunnel that feeds the idle jet. If you leave the slow jet uncovered you also would need to find a way to plug that hole or your main jets would be feeding the needle both through the jets and through that unrestricted hole. That would be real bad. I would leave the design alone, if I were you.

I do not run pods (and really don't believe in pods, but that is just me) but I know that pods, along with making carbs much more difficult to tune through all ranges, also may require rejetting as they can cause a lean running condition. Before you worry about getting the right size jets in there, though, you first have to make the bike run correctly through all ranges on all four carbs. Only then you you be able to determine if you need to adjust your jet size. You've got a ways to go before you get there.

Patrick

[DGXSER]

Patrick has it right.

On the early model carbs, there is a passage from the main, jet emulsion tube, to the pilot jet passage. If you leave the passage un plugged, it will cause alot of fuel to get to the pilot jets. Also, the main jets are larger due to the design of the passage, again it would play havoc on the fuel mix to leave the plugs out.

You do need to thoroughly clean all of the passages and those jets. You may find that will make all the difference for you.

[cywelchjr]

Leaving that unplugged would also mess up the main jets as the tunnel would also cross feed back to the main without that plug, it's a two way passage. Without the plug the idle is still ok, but as soon as anything starts coming through the mains at all, it's way rich, cause you get both the main jet fuel and the pilot jet fuel into the main area at the same time DAMHIK. So if the cross passage is there, the plug is 100% required for proper operation of the carb, it will not work properly without it.

[11Rider]

OK, well that answers that I won't second guess the engineers. I'm going out there with a guitar string to clean out the holes in the tips of the pilot jets and then do a thorough cleaning of all the itsy bity passages as you guys recommended. I have a good feeling that I'm on the right track thanks to you guys.

[natemoen]

I will just add this since you didn't specifically mention it. Along with the single small hole in the tip of that jet there should also me 6 holes around the side of the jet as well in a 2-1-2-1 pattern. If there arent those holes then you have the wrong jets altogether and just need different jets period.

[11Rider]

I will just add this since you didn't specifically mention it. Along with the single small hole in the tip of that jet there should also me 6 holes around the side of the jet as well in a 2-1-2-1 pattern. If there arent those holes then you have the wrong jets altogether and just need different jets period.

Thank you - the other holes are there.

I took the carbs apart and got all the jets out including the needle jets, the slides and all. With the exception of the tips of three of the pilot jets, everything was REALLY clean. Nonetheless I doused everthing and all orifices with Seafoam and blew everything out with compressed air. I notices that air did come out of the little holes in the venturi when I blew in the pilot jet orifice. I am real confident that I got the problem, with the exception that I'm sure I'll have to do some tuning like the idle mixture and synch.