Carb Mystery

[Norseman]

I have a mystery on my hands, and wondered if any of you had any insight.

I’m rather confused over a couple of issues related to the o-ring kit I bought from cycleoring and the actual carburetor on my GS650GLX (1981). First, when I checked the float bowl drain screw whether I had the fiber gasket or rubber o-ring, I found a very compressed rubber o-ring (flattened is a better word), but it is definitely rubber and not fiber. However, when I got the o-ring kit, Robert Barr had kindly included the drain o-rings, but they look significantly smaller than what would fit inside the drain hole. It looks like they would simply slip up inside the threads in the hole and not seal. Is there a third type of gasket (rubber, but much bigger)? By the way, the microfiche on several dealership sites clearly calls it an o-ring.

Also, when I disassembled the carburetor, my air screw (#1 Carb) does not have an o-ring nor does it have a washer below the spring (as shown in the carb cleaning series paper). Is it possible that some carburetors came without o-rings and washers on air screws? The alternative is some mechanic or the PO in the past forgot to reinstall the o-ring and washer on the air screw, but that’s not likely because the air screw caps were still in place and un-disturbed. Does anyone have any idea as to what is going on with the odd drain screw o-ring and the air screw mystery? I checked my Clymer very thoroughly, but apparently no one wants us messing with air screws because there's not even any mention of it. Thanks beforehand for any help.

Norseman

[Nessism]

Sounds like someone from Mikuni made a mistake when they assembled your carbs with regards to the missing o-ring and washer. You should put them back together properly - add the missing parts.

I'm not sure about your 650 but the float bowl drains on my 550 carbs look like molded soft plastic seals. You might want order some from the dealer to make sure you get the proper parts.

Good luck.

[t3rmin]

You can get the washers/screws/o-rings at MikesXS.com. The screws are a bit different but they seem to work; and if you just need the washer, then no matter anyway.

[chef1366]

I bet your washer and o-ring are still in the carb. Shine a flashlight in there and have a looksy.
But I'm not a betting man.

[Norseman]

You win (if you had bet)

Chef,

You are cooooorect, Sir. I took a bright flashlight, and sure enough, there those little suckers sat - all the way at the botton. Paperclip, straightened, little bitty hook on end, fished'em out easily.

Maybe you should make an occasional bet, Chef ? Now on to the drain screw washers. My best bet is probably the dealership...

Norseman

[bwringer]

On my carb drain screws, I, um... *cough*, improvised.

Well, OK, I'm a little ashamed to admit this, but...

I went to the hardware store, and bought some 1/4 inch nylon washers.

They've held up perfectly through several drainings and haven't leaked a drop in 6 or 7 years.

YMMV. Worked for me, though.

[Norseman]

Great Idea

bwringer, that's too cool - I'm going to give that a shot. I'm tired of running back and forth to the dealership and paying an arm and a leg for 26 year old parts. I'm not restoring, my objective is to make the GS650 as reliable and safe (for my son) as I can, but when an alternative works just fine - well, it works.

So, thanks for the heads-up and a solution.

Norseman