Where does each carb jet lead to?

[lcdrjoe]

I'm sorry to be so full of questions, but here goes another. I've got this 87 interstate starting up, but it's only really running on the right 2 cylinders (1 & 3). Essentially it's a 600 not a 1200 . If I squirt fuel directly into the inlet screens for 2 and 4 they fire up, and if I rev it up to 5k rpm or so, they kinda fire up, so I know the spark is there. I can open the drains on 1 & 3 and they have fuel. I've even taken the carb assembly out and held it upright so I can take the bowls off and make sure they have fuel and they did. I've had these carbs out and apart at least a dozen times in the last couple months since getting the bike. I've had them in the ultrasonic cleaner, replaced all the replaceable parts, stuck super thin wire in each hole, set the float levels per the tech manual, ... I'm wondering if someone knows where each of the jets comes out so I can make sure they are not stopped up internally still. These two are on the side the bike was leaning for the past 6 years in the rain, leading to the engine seizing up so completely. To my knowledge there are 4 jets/screws: 1: Main jet, 2: Slow jet, 3: Starter jet (can't take it out jet in the bowl), 4: Pilot screw. I'm pretty sure when I sprayed carb/brake cleaner in the main jet it came out the opening where the slide needle went in. I'm not sure where, if anywhere, the others came out. I 'think' the starter jet is supposed to connect to the pilot screw opening as well as the 4 super small holes just behind the throttle plate, but I'm certainly not sure. What I do know is that no hole I spray into causes fuel to spray out those 4 little holes. Maybe some of you guys know. As always, I appreciate the help and the knowledge.

[lcdrjoe]

In partial answer to my own question. I took out the pilot screws on #2 and #4 carb and sprayed carb cleaner in. I had taken off the elbow connecting the carb to the head for these two, held the throttle open, and had the choke on fully. When I sprayed into the pilot screw hole the cleaner came out the hole that opens when you open the choke. It didn't come out fast at first, but after a few attempts it came out nice and strong. Nothing seemed to come out of those 4 really small holes further back in just behind the throttle plate though.

[DenverWinger]

Had same issue with my 1100 this spring. Turned out to be plugged idle jets in #1 and #3 carbs. It would run on all four if I gave it some throttle (proved that driving around the neighborhood), but only #2 & #4 firing at idle throttle.

Don't have diagram of 1200 carbs, but those jets will need to come out and be cleaned. There's the little orifice hole thru the center, and then 8 more little holes thru the sides of the "top" end of the jet tube.... On the 1200 I think they should unscrew from the carb body. Pressed in on the '80 1100. These jets are the fuel path between the carb bowl and the pilot screw and the little hole behind the throttle plate. You should be able to spray cleaner into the idle jets and have spray coming out the pilot screw hole or the little port hole behind the throttle plate if pilot screw is not removed.

[lcdrjoe]

Thanks for the reply Denverwinger. I've replaced all the replaceable jets in all 4 carbs. Slow jet, main jet and its holder, pilot screw/idle screw, float needle & seat and little plastic filter below the seat. My fear is that they are somehow clogged up internally with rust not fuel residue. I'm putting the bike back together to get it in ridable condition, hoping it really needs to be run with lucas or seafoam in the fuel to help her out. Based on your recommendation, I'll take the carb assembly out again and blow air/cleaner through those jets.