Ugg. Hot today, but cool inside the shop so I ripped the bike apart.

Was dribbling fuel out the right side carb last time I thought we were ready to go, and has been sitting since then (A while. Don't ask how long. Too long. Busy with other crap.)

Expected buggered float valves.

Float valves/seats look peachy, but need new o-rings for the float valve seats (at least one does, so do both), new o-rings on the float assembly (needle valve o-ring) and new bowl gaskets. I also need to get real screws - allen heads or the like (first time I've had the carbs apart, but some previous idiot was in and didn't replace the crap screws, so I nearly didn't get the bowls off...)

Have been draining the carbs on a somewhat regular basis, so the grot in the bottom of the bowls is not too bad - just some powdery rust from the tank, no great globs of glue.

Local dealer is competitive except on float valve o-rings, where ronayers.com is ~1/3 the price, but I doubt it's worth bothering about. Would be nice to have all the o-ring sizes sorted out, since I bet that 10-100 of  the right size from McMaster-Carr is about what one costs from dealer parts. If I actually needed new float valve assemblies, ronayers is much better - $27-ish .vs. $41-ish. Over $50 some places.

Since the local dealer has a HD branch as well, I might finally get the HD Dyna Wide Glide front fork reflectors that I've been meaning to get since they were mentioned here years ago.

Did you check the float height to make sure that's all good? If the float height is too low, the bowls will overflow and relieve themselves through the intake trumpets.

Not yet. One float valve seat practically fell out, the o-ring is so bad. I doubt float height makes a bit of difference to that one. Leakage past the bad o-ring would dominate.

I'll set them before reassembling, but the rubber parts are in sad shape (other than the tips of the float valves, which look perfect), so those have to get sorted first.

If the floats are in good shape and you just need o-rings and gaskets, you might as well just pick up a couple rebuild kits for about 30 bucks apiece. That'll give you an opportunity to clean out the carbs and freshen them up a little bit.

I would suggest buying the individual rubber parts that you need from ronayers.com.  I've had issues with the needle valves that come in the aftermarket rebuild kits.

Cart from Ronayers with 2 of all o-rings and gaskets, and no needle valve set since that is the expensive part.

SKU                                                QTY   Your Price  List Price   Total Price
188390   O RING (13295-29900)                 2            $2.91   $3.51   $5.82
193462   O RING (13509-17C00)                 2            $2.91   $3.51   $5.82
186233   GASKET,FLOAT CH (13258-44B00) 2          $6.58   $7.94   $13.17
190798   13374-35C00 (13374-44080)        2           $1.74   $2.52   $3.48
190799   O-RING NEEDLE V (13374-46710)  2           $2.99   $3.61   $5.99
                                                                         Sub Total:   $34.28

Looks like I can get what I actually need for far less than $30 each. Local is not as good as ronayers but has no shipping (does have tax.) Some kits seem to forget the float bowl gasket...

This looks like the cheapest basic kit that does have one, but if I can walk in to my local dealer and get what I need without spending as much (seems likley) I'll do that - especially given the negative comments about aftermarket float valves in a different recent carb thread - And right here while I was typing this.

http://www.partsnmore.com/parts/suzuki/gs500/?filters%5Bcategory%5D=carb&filters%5Bfitting%5D=custom

Measuring the old, crunchy o-rings (so size may be wrong due to crunchiness and set), looks like (thickness - IDxOD):

Top cover tiny one - 1mm - 4x6mm $3.04 for 25 at McMaster
(13509-17C00)

Float valve seat - 1.5mm - 7x10 or 8x11mm $4.78 or $7.93 for 25 at McMaster ($6.32 for 7.5mm ID, the third possibility)
further measuring - 7x10 is too small - the seat body is 10mm, so 7.5 or 8mm ID would have to be it.
(13374-35C00)

Float ("needle valve" per parts diagram, just to be confusing) - 1.5mm - 6x9mm $3.60 for 25 at McMaster - Or possibly 5.5x8.5 @ $4.85/25
(13374-46710)

I have not pulled the needle seat (or needle jet) (the pesky one inside the carb throat for the big needle), which would be the remaining o-ring. I'm dubious about whether I need to, really. Things are not gunked up at all, just leaky down at float bowl level, and it appears to be happily in place. Took a stab at if for completeness, but it's not easy to get out, and would be easy to mess up, and It does not appear to need replaced now, so I don't want to make it need to be replaced by destroying it to look at its o-ring...or does it even have an o-ring - I think Haynes confused me by showing a picture of the float valve seat while claiming it was this part....

guess the other one bombsquad83 mentions is on the pilot screw 13295-29900

Will probably give up and pay too much at the dealer this time, and then measure those before putting them in. But if anyone has fresh ones (this is a 1990, two circuit carb) and a good metric measuring device, please do post the right sizes, because 25-packs of Viton from McMaster are less than buying two (sometimes 1) from the dealer on most of these sizes. Since they are Mikuni carbs, I'm assuming metric o-rings.

Bump de Bump - nobody has fresh carb o-rings and a metric ruler?

Sorry, just got mine back together a couple of days ago and since it seems to be running nicely so I don't think I need to pull it back apart.

Gave up, went to the dealer.

They were out of the pilot screw (tiniest) and top cover tiny o-rings.

I think I see those well enough as 1mm - 3x5mm and 1mm - 4x6mm to just order from McMaster.

The float seat o-ring appears to be 1.5mm - 7.5x10.5mm

The needle valve oring (the one on the float itself) may really be an oddball.
Or it may be an 008 (1/16 - 3/16x5/16 inch size) Certainly very close, and possibly close enough.


The All-American Harley reflectors were made in... Finland. 
Still better than nothing (what's on there now) or stock for front fork reflectors.

Quote from: DoD#i on July 25, 2012, 01:18:37 PM
They were out of the pilot screw (tiniest) and top cover tiny o-rings.

I think I see those well enough as 1mm - 3x5mm and 1mm - 4x6mm to just order from McMaster.

Look to be a perfect fit. Faster and WAY cheaper than having the shop get them from Suzuki.