GS450 idles at 3-4.5k

[Gambit]

To answer the other question about the butterflies, they seem fine and fully functional. No sticking.

[Gambit]

The air leak you are referring to is on the boot I'm assuming? From what I've seen, to test this I need to shoot some ether around the boot and see if that effects the idle speed. If it does, then I'll need to replace the boot. Cuz that sounds fun. I likely won't be able to hit this test until 6/23-25, work and leisure dependent.
I have not shaken it. I guess I'll try that too.
Edit: I won't be able to do this until at least Wednesday. I have to buy new jets regardless because I destroyed the old ones trying to get them out. I work during the same time that the bike shop is open.

[tkent02]

No just lift it up and down. That should make any leak get bigger or smaller which will change the idle speed. With pods, all of the carb's weight is supported by the boots, which are not really designed for that. Also they are thirty some years old, the weight makes them crack or tear. You can shoot anything on the boots to check for a leak. Carb cleaner, WD-40, most anything will change the idle a tiny bit. I like to use a propane torch (unlit) because it doesn't leave anything on the carb, doesn't attack the rubber.

It just seems that wiggling the carbs up and down will tell you the same thing a lot easier.

[Gambit]

I will try moving them around when I get it back together. The reason I'm thinking restrict the fuel is because something has to be burning in order to get that high of an idle. Since the fuel feed is vacuum based on the air side to motivate the slides up, I'm not sure how an air leak on the engine side would create more stuff to burn or higher velocity air from the air side. I would think an air leak would cause the mix to lean out and burn less, resulting in lower RPM. That is, unless the mix is being propelled out of the leak, but then I would think that any excess would be sucked out of the leak rather than going into the engine. I'm really just trying to understand the reasoning behind it. Not being argumentative. I just want to fully understand.

[Gambit]

Forgive me if I use my idle time to more fully understand the problem. I get that you have a theory that has proven correct many times with your experience. What I don't understand is why? Why does a leak in the boot cause a higher idle? Again, I'm not questioning your experience, I'm questioning the reasons it is true. The difference between an operator and an engineer is the understanding of why it does the thing it does. First, does the leak pull air into the flow? Or does the air/fuel mix escape? My thought is that the air might be escaping, causing a higher velocity of air through the carb, which in turn raises the slides, increases the fuel, and gives the engine more to feed on which results in the higher RPM.

[tkent02]

Air leaks in, more air to expand when it fires, so more pushing the pistons down, more RPM. Too lean is hotter anyway, as in a mix that is rich some unburnt molecules of gasoline carry heat away. Lean is always hotter than rich, unless it's so lean it can't fire.
At least that's my guess. Don't really know any more.

What I do know for sure is an intake leak will almost always raise the idle.

[1948man]

To answer the other question about the butterflies, they seem fine and fully functional. No sticking.

Could you visually verify the butterflies were fully (or almost fully) closing on slack or no throttle. Were the carbs off the bike when you evaluated the smooth operation of the butteries. There should be almost no open space when the throttle is slack. There is a "how to" on bench synching by Steve on BikeCliffs page.

http://members.dslextreme.com/users/bikecliff/images/carb_sync_notes.html

[Gambit]

OK fellas. Went and picked up some new o-rings for the boots. The ones that were in there were basically flush with the rest of the housing, so I figured I would just replace those while I had the boots off. I carefully inspected the boots to ensure they had no cracks, holes, tears, or any unusual signs of wear. They did not. I picked up the 120 main jets and installed those. It was gonna have to happen anyhow, so figured I'd get that out of the way. Now, my problem isn't a steady 4k idle. Now it bounces from around 1.5 to 4k. It instantly bogs whenever any throttle is applied, and then accelerates a few seconds later. Kind of a delayed reaction thing. Yes, the butterflies were visually closed. Again, I can take the throttle cable completely off and it wouldn't matter. It still does this. The idle screw functions as well as it can in this circumstance. If I screw the idle up to around 3k it just sits there, but still bogs at a twist of the wrist. This is with the choke lever down. If the choke lever is not fully down, the bike won't even start and instantly stalls if I change it during idle. There will be a video posted here shortly just as soon as I get smarter than my smart phone.

[Gambit]

Youtube has video too? ermergerd.

https://www.youtube.com/watch?v=Cnwv04szkA4&feature=youtu.be

[Gorminrider]

I can't add much to above
but for lack of not already been mentioned

Make sure the pods are not blocking any passages on the bellmouths of the carbs.

check the slides for proper operation slippery operation.... If you block the top passage oval of the bell-mouth, they should stay up. at least, mine do.

Restricting the air at the pods might indicate where the issue is, ...a clean cloth etc wrapped round? one side or both

ADD: maybe check the spark advance mechanism . I've never seen one stuck, but too advanced a spark might make your symptom.
and pulling a single spark plug lead off might also narrow the issue to a single cylinder problem dragging the other along with it

[Gambit]

Thanks Gormin. I haven't seen anything resembling a bellmouth on these specific carbs that the pods might cover. The only contact they make is around the rim, and those are round all the way (I checked this already due to a youtube suggestion.) I will try the spark connector suggestion, if for no other reason morbid curiosity. If several people have been over this thread that sound knowledgeable, and I've tried everything they've said, I may be offloading this bike and just using the proceeds for a down payment on a new bike. I really don't want to do that at all. What else is there to do?

It's funny. I have 6-7 folks that I know personally that ride, and all of them said they knew motorcycles. Yet, when I started asking questions like needles and jets, I got deer in headlights. None of them have half the knowledge of you boys. I'm thankful for the help. I'm just not sure it'll be enough.

[Gorminrider]

Someone here knows, but you've gotta figure it's a changing crowd of blind jellies that can't see or touch your bike. You can search the forum and with so many ideas and questions , one will ring the bell. But you have to be really plain. a half hassed spraybombing of carbs disassembled will not satisfy - You personally have to be really sure every passage is clear, every jet has been removed and cleaned.that the floats and fuel inlet needle are functioning correctly or none of our pellets of goodwill will hit the mark.
now the symptom is "Throttle is slow to respond" or "Throttle is delayed". per the video? basically you strangled something but what?
"Bogging" well, you'd be suprised how that turns out to be a single cylinder not working. Has for me. These bikes can sound deceptively good with just one cylinder happening!

Pods are a wild card for me-never had em ,but it should not be too hard to separate their specific tuning issues from the original bike. For one thing, you are likely doing the same to each one so both cylinders are going to be equally affected.

but
Since it's unlikely(but not impossible, unfortunately without a proper cleanup) that both carbs,pistons,valve sets,coils have the same issue, it'd be good to find if a difference exists side to side. If there's no difference, you can look elsewhere, before returning to the possibility that they are both b*ggred in the same way... twins are so easy. . Not good for the bike longterm but it should start and run with just one. If pulling the plug to do this keep a plug in the lead clamped to engine or otherwise ground that plug lead

someone else here might correct me please but
The stuff about "air" and lean and advanced timing should also have the symptom of no power,I think... so putting a lean/advanced bike in gear is not going to be the same as a bike with "too much gas".Too much gas will keep going with a footbrake applied lean,advanced should falter pretty quick .

The "enricher" aka "choke" is a possible. These aren't butterflies as you know-they are sucking gas from the bowl so If it's not turning off all the way on one or both carbs, then your bike would be getting too much gas...yes, full "choke" will nearly kill a warmed engine-perhaps what you are saying per

If the choke lever is not fully down, the bike won't even start and instantly stalls if I change it during idle.

but partial "choke" keep it running highrpm with power, (unlike the lean condition)
These and the idlemix are hard passages to clean by the way. I cleaned mine mechanically and test that each has flow by pumping solvents through them.

[tkent02]

This is with the choke lever down. If the choke lever is not fully down, the bike won't even start and instantly stalls if I change it during idle.

OK, on the 450 the choke lever down, is the choke fully on. It's reversed from the other models. And it's not actually a choke.
The choke opens a valve which allows a rich mixture of fuel and air into the engine through the normal ports where the fuel comes in at idle. Both the fuel and the air come from separate passages in the carburetor. Perhaps the fuel passage is blocked, so when you open the choke you only get air? Perhaps the air passage is blocked so when you open the choke you only get fuel? Could be the passages leading to the fuel screw are blocked? I'm not sure exactly what, but there is something going on in there. Sorry I don't have a carb here to look at, can't remember exactly but that is the next place I would be looking.

If you need full choke there is a problem with your idle circuits, the choke circuit, or a combination. In moderate weather it shouldn't take much choke. In hot weather shouldn't need choke at all even with a stone old engine, or maybe just a tiny bit until it fires up and then none. Full choke should only be required in sub zero temperatures. When you use full choke in cold weather the idle will be pretty high. 3,000 or so, maybe more.

The fact that if you turn the choke off it instantly quits says the carburetor is not getting fuel through the normal path. Very common symptoms on a bike that has sat idle a long time.

[tkent02]

Also looking back through this thread, I see no mention of any carb cleaning. No ultrasonic cleaning, no 24 hours in The Dip, nothing. What carburetor cleaning have you actually done?

[Gambit]

Tkent, the most carb cleaning I've done is taking off the bowls, the main jets, the pilot jets, the needles/slides, and removed some deposits around the butterflies. I soaked all the parts that would fit in a jar that were all metal for about three days in total. switching out the carb cleaner at the end of day 2 (did not soak the rubber on the slides at all, was very careful not to spray them even a little.) I did just get in the O rings from cycleorings.com. I have a couple things to try this Sunday, thanks to you folks and a few random guys I met locally that ride and seem to know their stuff. I have not sonic cleaned the carbs. Don't even know what I'd need for that.
As for it sitting, the PO said that he rescued the bike from a bush. So, I'm thinking he got to the same idle issue and gave up. I don't want to fail like he did. I've got a list of stuff to go through now, and most of it seems fairly straight forward. I'm going to try and get video of the carbs torn down and show what precisely what work I've put into this thing. This should alleviate some of the questions other respondents my have. PLEASE let me know if there's anything specific you want me to catch on film. I am not at all hesitant to film stuff for you folks to better help me out.

PS, when I mount the carbs into the boots, it sets in once, and then I push harder and it moves more. My current suspicion is that I've pushed them in too far and there is not a proper seal where the boots and carb body meet. I'm going to get some new cinch rings while I'm at it because I'm not completely convinced the ones I'm using are doing the job. I'm hoping this is the error I've been searching for. Just haven't had time to test the theory.