Lets start simple...

Lift the tank slightly, turn it sideways so it sits on the frame with the petcock over the carbs. Use a towel or something if you have the fairings on to prevent scratching them.

Once in place... turn the petcock to prime for 4 mins. After 4 mins, turn prime off. Carefully remove one and only one of the fuel lines. Wipe it off with a clean town so you don't get gas on your lips. Blow on the fuel line... hard. Do that several times. Wait 2 mins.. Do it again several times.

Did you hear any bubbles, or were you able to move air through the fuel line at all? IF yes... one of those carb bodies have a leaking float needle. If no, put the fuel line back on and start again.

Set to prime for 4 min, turn to on... pull off the other fuel line, wipe it off... blow. Repeat the full process you did above.

If you do that on both, and still could not move any air... then take the air box off the bike. Set the petcock to prime. Check every 10 mins. Leave it sit for a few hours... again, check every 10 mins at least.

Do you see fuel leaking?

If no... then change the oil... and run the bike again. This will verify it wasn't a situation where you just had a lot of gas still in the oil cooler from the last time, or something like that.

Krey

Not to take away from the reply above, but have you confirmed that the ignition is good? I suck with carbs but can get by as long as there is a service manual. Does all cylinders have spark, are the plug wires at the correct cylinder and compression in spec?

Kreylyn, I did the test to blow air through both lines and was unable to pass air through either one. As far as I can tell, no gas leaked with the airbox off either. There are no visual signs that the carbs are leaking, and if I manually feed them with a funnel, gas stays in the line and doesn't continuously run out. The reason I suspect that they are leaking or doing something wrong is that the plugs are fouling black and wet with fuel, especially cylinder 1. The bike will also not stay running at idle for very long, and if it dies, it takes a while of sitting before it wants to start again, which to me would indicate flooding. I could be wrong, though. Is there anything else that would be making it flood out? The A/F screws are currently set at 2 turns out due to it being too rich at 2.5.
Here's a dumb question: Are those turns full turns around in a 360, or is a 180 counted as a full turn? I have been treating 360 as a full turn. Also, should the lightly seated position be different on each body? They seem to like to seat in different positions. I did notice carbon build up in the exhaust pipes, and there is a bit of white smoke that comes out of the exhaust if I rev it up to about 7k. What doesn't make sense is I thought white smoke meant lean, but carbon build up means rich.

Rperry, I have confirmed good ignition. This bike starts and runs, but doesn't like to stay running. I tested spark on all 4 and they were blue, which I believe to be the correct color. The ignition coils and wires are new, but I have also tested the old coils with the same results. Spark plug wires are left hand coil having 1 and 4 and the right has 2 and 3, which is what it's supposed to be as far as I've seen in threads here. I have NOT compression tested, because I did not think it could be an issue. The bike has ridden, while poorly, in the past. At one point I had it out for a 25 mile run, but with the first set of carbs. Besides needing to be revved up a little bit, it ran fine.

Here is a YouTube video of the bike running for reference. My throttle cable is not hooked up to the bars, because it's in need of replacement due to fraying. My new one just came in today. The choke cable is also not hooked up, as the new one of those came in today as well. Sorry about recording vertical and clearing my throat during it. I can redo it if necessary. The bike also did something new: hanging revs. I don't know if it's a vacuum leak or out of synch carbs, but I replaced the intake manifold boots with an eBay set as well as bought new replacement o rings for them from eBay, and they are all installed correctly and facing the correct direction. Airbox boots are tight as well, so I'm really unsure why this is happening now...

Edit: actually, I'm dumb. I bet it's hanging because the vacuum line for the petcock wasn't capped. The bike still does die out when it is capped off though.

Full turn is indeed 360 for the a/f screws. Have you tested for vacuum leaks both sides of the carbs too?

When I had issues with potentially leaky carbs it was suggested here to get them off the bike and set them up over 24 hrs with an auxiliary tank to check there was no leak at all. Might be worth you doing the same to ensure float needles are fully seating.

I did have a situation where after a carb rebuild I had a load of fuel sputter out the back of carb one which was possibly how my oil got contaminated first time round assuming that with the air box on this would have got sucked into the engine. I can only assume that something wasn't as clean as I thought it was within carb one. Had to use a spurt of brake cleaner direct into the carbs to get things ticking over, since then and following a float height adjustment and oil change she's ran just fine. Only noticed this happen when I ran it without the air I on and sadly no one offered me an explanation as to what might have led to the fuel spurting.

Also not capping the vacuum port from carb 4 made my revs hang too so hopefully that's the all that was up with that issue for you.

Stupid question, you mention the choke not being connected up, if I starts mine with little or no choke it will die pretty quick, are you getting it up to running temp just holding the throttle open?

Is the oil in it right now gas free? If there is any fuel in the oil it will cause the bike to run rich. That would have to be resolved.

I'll mention that "adjusting" things like the a/f screws because the bike is running rich... when the a/f setting is where it should be, it adding problems. Start at a baseline, and then determine why it's running rich before making adjustments like that. You end up with a lot of conflicting issues when you don't.

So, check the oil.. replace if it has gas in it. Set the a/f screws at 2.5 turns (US model right? Cause UK would be 1.5 turns). Are the plugs new? I'd replace if not. The coils are blue... that's not stock unless painted. Are they aftermarket coils? I've run across several recent reports of them going bad recently, so I'd check those by testing them. 7mm solid core plug wires? Plug boots securely screwed onto soft pliable wire?

Things that could make the bike run rich other than leaking past the float needles... improper height on the floats, choke sticking open, fuel in the oil, bad or missing pilot jet plugs on the Pre kats (they need to fit tight!), drilled/damaged/improper sized jets.

Does the carbs have a jetkit installed? If so, how many slots on the needles. Any white nomex inserts in the bottom of the slides?

Krey

Well, I guess halt everything. I don't know what I'm going to do at this point, because I finally went out and got a compression tester. The results were 95,100,81,87 for cylinders 1-4 respectively. I guess I could try sending it for a valve adjustment, but it's probably going to be expensive and it might not even help. I'm not willing to do it because these are shims, and I really don't have the steady hands for valve work. Carb work is bad enough. Everything out here is closed for the night, so I can't call and get an estimate from anyone yet. I really hope they are just out of spec, because if it's anything worse, I will probably be scrapping the bike. I'm broke enough as it is, I can't afford to bring a completely dead engine back anytime soon.


Some answers to questions: Jets are all stock in this carb set, the rubber plugs are good for the pilot jets, the needles have one setting and are the stock ones. I don't know if gas is in the oil for sure, I think my nose is playing tricks on me because it sometimes smells like it and sometimes doesn't. Could that also cause low compression?????

Ignition coils are NOT stock. I replaced them for peace of mind due to the clips being broken on the stock ones. Didn't want the wires to just come out on me. I do have the stock ones in a box in my house though. The boots are screwed into the wires tight and do not randomly fall out or anything. A few days ago I did take these new coils off and put the stock ones back on just to see if anything changed, and it did not.

In that video the bike started without choke at all. If it's ever needed it, I did it manually. The throttle was also completely off as well...

Does the compression tester setup you got have a leak down test option? If so, do that... it will tell you quickly if it's rings, valves, or other.

Valve adj is simpler to do (even shims) than carbs.

Gas in the oil would not necessarily cause low compression, but it would definitely cause all of the other issues you have.

And last thing... I don't know where in VA you are... but I do offer bike work/parts and shop time (you show up and I show you how to do it) for cheap if not free (if your doing all the work, I'm not gonna charge you). IF you wanted to cover my "time" of hanging out and talking bikes/shop time... Pizza and soda works for me.

Right now I have like 2 or 3 600cc engines that are probably good sources for replacement parts to fix an engine, and enough parts to put together probably 2 or 3 bikes. Offer is there, up to you.

Hell, I even have rustic camp site avail if you want.

Krey

Compression tester doesn't have a leak down test option. I'm in Virginia Beach, so about halfway down the state. You're about 7 hours out from me, sadly don't think I could do it even if I wanted to. I don't have my own car anymore and don't think I could borrow my mom's​ truck for that. I also have to start college on the 28th and then I'll be even farther North.

I went out and re tested the compression after adding a little oil to each cylinder, and they only went up about 5 psi each. Does that rule out bad rings because it didn't go up to the proper psi?

What will shims entail? I've got feeler gauges already, but I think you need something else to actually adjust. The bike has 5545 miles on it according to the clock, and the bike sat around for a hell of a long time judging by the shape of the tires and brake fluid it had, so I believe that is the true mileage. Adjustments are needed every 4k miles on these if I remember correctly, so could 1500 miles really do this?

Edit: I'd also like to point out that the compression test was after running the engine for only about a minute, because it does not like to stay running. Perhaps my low compression isn't actually low at all?

I'll be honest here: I had never even picked up a wrench before buying this bike, so this has been a good learning experience. I've done a stainless steel brake line install, cleaned calipers, changed fluid, changed oil, rebuilt two sets of carbs perhaps both successfully, taken off wheels, changed chain and sprockets. I've also added $400 or so worth of tools to my room as well. Everything I know about working on vehicles has been from this alone, so if I say something incorrect I apologise in advance.

Did you have the carb butterflies fully opened when you did the compression test? (basically, throttle wide open)? If not, that would give a faulty test.

Only 5 psi diff tells me there isn't a ring problem. And they are all pretty close, so... I'm gonna say the test is the issue in some manner, either the tool or the process is giving false readings.

IF it is just cold engine (I would still expect higher around 110 or 120, but that aside...) normally the bigger issue is seeing a major variance or difference.

I honestly don't know how an engine with 5k miles would fail that badly on all 4 cylinders so equally, so I wouldn't write the engine off yet.

So... I'd change the oil. Rotella T6 will work fine for the change, it's like $21 for a gallon so not that expensive, and again a lot of the issues you mentioned are highly indicative of fuel in the oil.

Shims... shims are the adjustment. You use a feeler to check the clearances, then change out shims with different thicknesses to make the clearances where you want. Shim kits can be purchased so you have a variety of sizes, or you can just check them and order specific ones. You can also check with the local suzuki dealer if they have some in stock (as part of their valve adj on other suzuki bikes) and see if you can locate singles that way.

Do a shim valve adj search on youtube for visuals of what I just said.

Krey

I wrote that up some time ago, I'll locate it for you. It's best to buy the kit, 4 of a multitude of sizes. You'll also need a micrometer. Not necessarily but, it does make it easier since the shims do wear some and the original size stamp may no longer exist.

Here is one that purplehaze wrote up. Spot on.

I used a Harbor Freight compression tester, sadly. It had good reviews online and I figured I'll only need it one or two times so this should work. I don't know if it did. I will get the oil changed soon, do you recommend changing the filter again too? That bad boy is pricey around here, I paid $15.75 for it last time. I may end up doing a compression test again to see if it changes anything.
Also, the butterflies were open fully, yeah. All spark plugs removed and held starter until the gauge stopped rising.

I'm unsure if I'm going to be able to take on the valve job myself. Looking at the guide 92xjunker posted it looks like a lot of small parts that are easily lost. I don't have a garage, so I do all my work in the driveway. It sucks, and I guarantee I'll have one in the future.

I'm going to call a shop tomorrow and get an estimate. If the wait is going to be more than a few days for them to even look at it, or it's going to be super expensive, I'll do it myself. At this point, I'm thinking I'll be doing it because last time I called a shop which was in April, they told me I would be waiting THREE WEEKS before they could even take a look at my bike. That was actually to remove a few stripped screws on the fairings, which I was able to get out on my own.

This is kinda crazy, going from what I thought was a carb flooding issue to this.

I had the valves adjusted at a shop, they told me there were a few out of spec. They adjusted them and compression tested, all cylinders tested at about 175 psi. I don't know where else to go from here, because the bike still doesn't hold its idle.

I've made several posts on Reddit about this as well, and nobody is telling me anything besides valves or carbs. I'm completely lost because I actually swapped everything to my old carbs and it still doesn't run. I cleaned those as well, and they were not even gummed up like the new set was. I've got two sets of emulsion tubes that both looked good and not egg shaped, I've tried both of those. The jets were soaked in B12 and then ultrasonically cleaned and had carb cleaner generously sprayed through them.

I'm confident that the cleaning was efficient on both sets, so I don't know what has gone wrong. I found a video online on how to set the floats as well as read several threads here, and I quadruple checked each one. They are all at about 15mm, which I know is a little high, but should be within spec. I've tried setting them to the lower spec as well with no change.

Is it possible more has gone wrong with the engine? Could this be electrical? I'm tempted to dump it at a shop, but it's gonna be a whole lot, they charged $275 for the valve inspection and adjustment. They wanted $86/hr for SIX hours to do the carbs, and I told 'em hell no. Now, it looks like it could be the only option.

I'd also like to say that it seems like it's not pulling as strong of a vacuum on the hose for the petcock after the valve adjustment. I don't know if it was just messed up before or what, but it seems fucked up.

I was able to watch the YouTube video for the first time due to no broadband.
Sounds like a fuel delivery issue or ignition because there is clearly a cyl/s not firing correctly. I would get rid of the aftermarket ignition coils and wires and search out a set on ebay. They are relatively cheap and change or clean the plugs at the same time. Then change fuel hose, filter, and petcock vacuum line. All 3 of them should be less than $10 at any autopart store by the foot. Check the petcock for proper flow or blockage. I reread and see that you have stock coils and they did the same, either way I would make it stock again for reliability, follow service manual to check voltage, resistance, and grounds for coil packs.

I need to go back and see if you already done any of this but that's where I would go from here.

Once upon a time I lived in va beach, which shops are you using? Is there still a shop on mercury Blvd in Hampton between Aberdeen and Jefferson?

All fuel hoses were replaced with brand new ones. Petcock line I unfortunately haven't replaced because nobody around me has one like it. I've looked it over and can't find any damage to it and it is still nice and soft.

I used Cycle World this time, they were alright. Before them, I used 757 Cycles and had a very terrible experience with them. Manager tried to take advantage of me because I'm young, thought he could charge me twice for removing wheels, etc. Ended up with him calling me a "spoiled little douche." They're never going to see my business again.

Other than these two, options get pretty thin. Can't take it to any Harley shops, and the custom bike shops around here don't want my business on this bike.

It's pretty much dealer or nothing, which is why it went to Cycle World. I'm not sure if there is still one there, I really don't know that area very well and can't find anything online about one, but maybe I'm just not looking well enough.