GS850 Carb Mystery Hole

[Guest]

Hey guys. I didn't see an intro thread, so I'll roll that into my first post here. I've been into old Japanese bikes since I started riding years ago. Previously, I'd owned all Hondas, but the GS850 just sort of had something that called to me. I found this forum by googling about and have been stuck between here and BikeCliff's site ever since. You community is wonderful! The resources here are amazing! None of my other bikes have led me to a community so knowledgeable and friendly to rookies like myself. Now, onto my question.

I've been following the GSR greeting post and have gotten to my carbs. The break down has been pretty straight forward, thanks to the guides you folks have linked, and I've already got my o-ring sets and so forth from Mr. Barr. The bike had a nasty backfire from cylinder 3 when I brought it home. Some fiddling seemed to help a bit, but I knew I'd have to get into those carbs. Lo and behold, in carb 3 I found a hole that was plugged in all the others with a rotten, half melted bit of rubber in it half stuck to the float bowl gasket. The opening leads right up into the carb throat just behind the butterfly. Anyone have any idea what's going on here and how I can address it? I threw together a little imgur photo album to give a better idea of what I'm looking at. Please let me know if another picture format would be better for you guys.

http://imgur.com/a/O17VG

[tkent02]

Those plugs fall out once in a while, the bike runs like crap.


I got my 1000E for a song because of that, the PO thought it "Blew a ring"

[Hedonaut]

So what would it be called and where do I purchase a replacement? The old one is little more than a piece of melted rubber and I couldn't find it labelled in any diagrams. Thanks for the quick response!

[loud et]

On e bay just search Suzuki GS carb rubber plug.
Set of 4 for 9.99$
Or many other choices there.

[Crankthat]

What is posted above on where to buy.
Shown in the link is the plug that goes in the post.
Not the part you are referring to?
What I believe you are referring to is the hole you can see your finger through in the second picture.
Did not realize that was a plug myself.
That would explain the rubber o-ring that sits on it.
Surprised I never noticed it is a plug as I have taken apart a few!

EDIT

Or are my carbs that different?

taking another look, yes they are.
Still not satisfied that the link is the correct part though.

[Nessism]

Doubt you will find those plugs for purchase. Your best bet is to post in the Parts Wanted forum for a spare carb body. You can hacksaw your way toward freeing one, then use JB Weld or similar to affix it back where it belongs.

[cowboyup3371]

EDIT

Or are my carbs that different?

taking another look, yes they are.
Still not satisfied that the link is the correct part though.

I took another look and saw what he was pointing to - deleted my post.

[Hedonaut]

A friend of mine as a small, amateur machine shop. Could you guys think of any reason not to make a little cylinder plug out of aluminium that fit the hole well and stick it in with jb weld? Is there anything about this piece that has to be precise other than the fit? Incidentally, what purpose does this thing serve? It looks like it's just a bit to make the carb easier to manufacture.

[tkent02]

Just an aluminum plug. JB will eventually fail around fuel, it needs to fit tight enough to stay in place.

[Nessism]

A friend of mine as a small, amateur machine shop. Could you guys think of any reason not to make a little cylinder plug out of aluminium that fit the hole well and stick it in with jb weld? Is there anything about this piece that has to be precise other than the fit? Incidentally, what purpose does this thing serve? It looks like it's just a bit to make the carb easier to manufacture.

Good plan. Post some photos of the plugs. Think the carb bodies are zinc so it would be ideal if the plugs are made from that.

[Hedonaut]

The part that came out was all rubber with bits of it stuck to the sides of the tunnel it was in going all down the tunnel. I wonder why the other carbs have a metal plug while this one had a chunk of rubber.

[tkent02]

Someone tried to replace it with rubber. Must have worked for a while.

[Nessism]

Rubber plug because the metal plug fell out awhile back...

[Hedonaut]

That does indeed make sense. I'll share what I come up with as well as the host of other questions I seem to be generating. Thanks for the help, guys. If anyone ends up with a stock source for one, please let me know.

[Crankthat]

Could he use gas resistant epoxy?
Would the temp changes you would find in that area make that a bad idea?
If so what would be recommended.

Possibly having another plug made?
I have a torch tip cleaning kit.
Really small drill bits to turn and clean the passages.
Have drilled holes in plastic to insert paperclip pins to hold things in place.
Not sure if the bits would drill well in harder materials, but you should be able to find some that would.