Mixture Screw compatibility (gs450 issue) and gs500 carb info

[Guest]

Sooooo I was checking over things and fubared one of the mixture screws in the carburetor.

It's not impossible to get out, I can do it VERY carefully, but the next time I take it out, it has to be replaced.

Problem is, I can't find anything for them. I don't know if I can use mixture screws from another bike using the bs34 carburetor or not. I know that even though they are bs34 carbs that they do have some differences.

ANYWAY, I'm switching to the GS500 carbs soon anyway, but I'd like to have the original carbs in good working order.

On another note, is the temperature drop really making me run this lean that i am popping all the time? My mixture screws were already 3 full turns out with only pod filters, otherwise stock.

[sam000lee]

Since it's not rusted in you could probably use an ez-out type extractor pretty easily. If it's backed out all of the way and you're trying to get it out of the carb body you can shoot air through the other end of the passage. If I remember correctly its one of the little holes that is before the butterfly valve on the inside of the carb mouth. I've done it with a can of dust-off and a little rubber piece that I drilled small holes in to use as a seal if you don't have an air compressor (I saw from your intro thread you were *thinking* about getting one).

As for a replacement, I'm pretty sure that some of the Yamaha XS's also use the bs34 carbs: I *think* that this may be the correct part, but you should try to verify: https://www.mikesxs.net/catalogsearc...cat=&q=48-5012

[pete]

I thought I lost one of mine during the rebuild, could not find a suitable replacement anywhere at all. Because they're covered on the parts fiche, there is no part number around to see if a replacement exists at Suzuki either... fortunately I found it.

If you get desperate I still have my stock 450 carbs here, only good for parts as the diaphragms are shot so I can send you a mixture screw if you need.

The one linked by Sam (Part 48-5011) looks familiar though... probably cheaper than me posting one from here

[Boba]

Since it's not rusted in you could probably use an ez-out type extractor pretty easily. If it's backed out all of the way and you're trying to get it out of the carb body you can shoot air through the other end of the passage. If I remember correctly its one of the little holes that is before the butterfly valve on the inside of the carb mouth. I've done it with a can of dust-off and a little rubber piece that I drilled small holes in to use as a seal if you don't have an air compressor (I saw from your intro thread you were *thinking* about getting one).

As for a replacement, I'm pretty sure that some of the Yamaha XS's also use the bs34 carbs: I *think* that this may be the correct part, but you should try to verify: https://www.mikesxs.net/catalogsearc...cat=&q=48-5012

It's not rusted, I think I'm just abusive and not careful.

I hate extractor screws. I never have good luck with them. They always end up making things worse for me. It is 3 turns out, but not backed out completely. I can get it out, I just have to be super careful since this last time I was going to fast and slipped, biting an edge off the screw slot. As far as *thinking* about getting some tools...

https://scontent.ftpa1-2.fna.fbcdn.net/t31.0-8/15289173_1879933978892956_7739653801916339156_o.jpg

I'd post the image directly but it's big and I don't know how to resize using the forum's img structure. I thought img=300x200 would work as it does on a few other forums I use that use bbcode but not here.
Anyway, that's me in a garage here that lets people use the garage to work on their bikes. I invested in the garage so I can go in and use it within reason. All tools and equipment I can desire!

I've looked at a lot of the bs34 carb users. The problem is that I'm not sure the mixture screw is the same or if the design was slightly different. I do know that the bs34 on one model can be significantly different from another. Not to say that they aren't somewhat interchangeable with some fabrication, but they are definitely different enough that I'm worried the mixture screws aren't the same at all.

I have thought about just ordering one here and there and seeing if any are the same, but after a while that can get expensive.

I thought I lost one of mine during the rebuild, could not find a suitable replacement anywhere at all. Because they're covered on the parts fiche, there is no part number around to see if a replacement exists at Suzuki either... fortunately I found it.

If you get desperate I still have my stock 450 carbs here, only good for parts as the diaphragms are shot so I can send you a mixture screw if you need.

The one linked by Sam (Part 48-5011) looks familiar though... probably cheaper than me posting one from here

Thank you! If it turns out the part I order doesn't work I will message you.

In the end, it's not terribly important. I received some rough shape gs500 carbs in the mail that I'm breaking down (currently soaking the screws in PB blaster, might have to flatten two side and take some out with a wrench). I should be okay to rebuild them as long as the screw come out, which I think they will. They aren't terribly rusted, just look like they haven't moved in 20 years.

I read either in your build posts or Big Rich's the jets to start with a baseline for gs500 carbs. We will see how it end up. xD

[pete]

The GS500 carbs are definitely the way to go.

My motor is stock except that I'm running 2001 GS500 camshafts and carbs. I run velocity stacks with foam filter over the top and have a 2 into 1 reasonably free breathing pipe on there.

With that setup I have 20 pilots, 65 mid mains, 132.5 mains, and I have the needle on the middle notch.

[Boba]

So I bought these not paying attention:

http://www.ebay.com/itm/201698962341?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

As you might be able to tell in the picture (I didn't at first), these are not 89-00. These are later model year 04 and up. When they arrived I started taking one side apart and took the screws in a tin to lowes to get stainless allen screws. During taking them apart I was surprised to see the TPS, thinking "Huh... TPS sensors. Cool."

Then as I took them apart and had the bowls in my hand I thought, "Weird, I thought these had a little nub with an o-ring... and the bowl gasket looks different... now that I think about it, aren't the diaphragm caps supposed to be black... and why is the idle set screw white... these are so different than the write ups and pictures I've seen..."

SO NOW... I have 04+ carbs for $50 and they are in good condition. I don't think they've ever been opened before and I had to use A LOT of PB Blaster to get some of the screws to budge. Even then I had to use vice-grips to remove some of them. The aluminum is very oxidized as you can see in the pictures.

I bought a bunch of SS allen bolts as I said along with a small bag of washers for where they are needed. I pulled the one carb apart in a hurry and forgot to pull out the float needle seat.

Pete, where did you get a rebuild kit? Cycle o-rings doesn't seem to have an o-ring and gasket kit for these.

[Nessism]

The pilot screw has a lot of meat on the threaded portion. If you use a thin metal cut off disc and cut the slot deeper in the screw the buggered part on the top won't matter. Of course this assumes you can remove the screw to cut it.

[Boba]

I can definitely get it out. Thank you because that's EXACTLY what I was staring at today, whether or not the mixture screw would retain enough integrity for further use should I decide to cut a slot in.

If only there was a dremel bit that cut allen hex holes xD LOL