Hanging Idle (I know, but bear with me) and different carbs

[LambBrainz]

Hey all, so I'm having the classic "hanging idle", but mine also seems to increase as well. I'll get the bike running, it'll be fine and then sit high and sometimes keep going up on its own. I've read that this can be an air leak issue and I've tried the unlit propane torch trick and the RPM didn't move no matter where I put the torch. I'm not saying it's not a leak, but I found that curious and I'm not really sure of any other reliable way to test that. The boots are also still pretty soft and I don't see any cracks (also they don't have o-rings? Picture below)

While we're at it, what carbs are these? Supposedly this model has the BS34SS but I'm pretty certain this is the BS32SS (notice how the intake side only has 3 holes instead of 5). With that, how many turns is the fuel mixture screw (in red of other picture) supposed to be


IMG20260328173740_preview.jpg

I've cleaned these, checked all the holes, verified there's no tears in the diaphragm, the slide seems to move correctly. I've adjusted the float height to what I _think_ is correct (around 22mm. It was at 17). I'm at a loss here

To recap:

[1] Any ideas on the weird idle? I was running rich (confirmed by checking spark plugs) to begin with and I thought I fixed it but now it's weird
[2] What is the correct fuel mixture screw setting for this carb? (Right now I'm around 2 turns out)
[3] What is the correct float height for this carb? (I think it's around 22mm, which is where I am now)
[4] What is the recommended place to get o-rings now? (From looking in the forum, I saw that cycleorings is no longer operating)

Thanks everyone

[LambBrainz]

Other picture. The red boxes are fuel mixture screws

image.png

[LambBrainz]

Boots between the carb and engine. Good condition, not hard, no cracks, and weirdly don't have o-rings. Just these big ridges that fit into the carb

IMG20260402184449_preview.jpg

[Syd]

Take one of the air intake manifolds off and take a look at the manifold to cylinder head face of the manifold. The O-Rings will be at this location. If they are cracked or flat they will allow air to pass into the fuel/air mixture on the engine side of the carbs. This is a common problem. If they have air leaks, you'll find it pretty dificult to tune the carbs.

[LambBrainz]

Take one of the air intake manifolds off and take a look at the manifold to cylinder head face of the manifold. The O-Rings will be at this location. If they are cracked or flat they will allow air to pass into the fuel/air mixture on the engine side of the carbs. This is a common problem. If they have air leaks, you'll find it pretty dificult to tune the carbs.

Oh man you're right, I totally forgot about that. Now that you mention that, my old Honda was the same way.

They're pretty flat. Again, I'd be surprised if this was the cause given that the propane torch didn't cause any jump in RPM, but I'll replace these anyway just in case. Thanks!

IMG20260402194038_preview.jpg

[Big T]

Nessism is supplying O ring kits now

Look for his post in Parts and Services

2 1/2 turns out is a good start on idle mixture screws

Service manual should be in the bikecliff site


Gsarchive.bwringer.com

[gustovh]

Check your valve gap, tight valves can mimic vacuum leak

V

[LambBrainz]

Nessism is supplying O ring kits now

Look for his post in Parts and Services

2 1/2 turns out is a good start on idle mixture screws

Service manual should be in the bikecliff site


Gsarchive.bwringer.com

He responded and said the 450 ones didn't work so I might have to find some or make my own

I have all the service manuals for this bike but they have different carbs than the ones I have here

[LambBrainz]

Check your valve gap, tight valves can mimic vacuum leak

V

Interesting, I'll add that to the list to check tomorrow. Is there a recommended place to get shims? I see them on www.cmsnl.com but didn't know if there were any other recommended places

[Big T]

Z1 Enterprises for shims
or, check with your local Suzuki dealer

[bwringer]

Z1 Enterprises for shims
or, check with your local Suzuki dealer

Yep, Z1 is a good source once you know what you need:

https://www.z1enterprises.com/valve-shim-295mm-220mm-330mm-suzuki-g-1.html

The kit doesn't make any sense, because you'll never need half the sizes. Valve clearances tend to decrease, so you need thinner and thinner shims as the miles go by. Once I see what's inside an engine, I usually plan ahead and make sure I have a supply of the next sizes down that might be needed.


Cycle Recycle II is local to me and that's usually where I get shims when my collection needs augmentation.

They sell online, of course:

https://www.newmotorcycleparts.net/motor_parts/valve_shims.html