Carb trouble? What is this ORing? & Hello

[pakuna]

Hello!

Firstly since this is my first post just want to say a big thank you to everyone maintaining & contributing to this site. I've spent hours on here & it's been a huge help so far.

Anyway, bought a 2006 GS500F about 6months ago (first bike) & it's been pretty great until about a couple of weeks ago. After a day in the rain the bike lost a lot of it's power, it reved, but it would not pull very much at all (hadn't really noticed a any problems before this). Decided to take a look into it myself & found that the left carb would spew fuel into the K&N (lunchbox) air filter. Figured it's a leak in the carbs somewhere. Took it apart replaced some O-rings gave it a good clean (pretty dirt & some grass had gotten in there somehow) & put it back together. Ran well for about a week (light riding) & then I noticed a similar thing happening. At a red light the idle needle would drop just below 1k RPM & would get close to stalling. Looked underneath the air filter & sure enough it was dripping (not very much mind you). It would still run fine at higher revs but occasionally idle lower than it should & leak fuel into the air filter.

Took the carb out again to double check everything & when I was putting it back in a mysterious Oring appeared underneath the right carb with the dimensions 34mm outer 27mm inner & 3.5mm thickness. Looks like these.

http://www.amazon.com/3-5mm-Black-Silicone-Rings-Gaskets/dp/B00A74IDLC

Anyone have any idea what it is & where it's from? I still put the bike back together & took it for a ride afterwards, it's better, but the idle fluctuates a bit (very fine) and the bike doesn't sound as consistent & steady as it did. If anyone happens to know what's going on here please do tell, it's starting to get frustrating.

Thanks,
Pakuna 

[Mxr261]

Could it be this one?

[pakuna]

It's much larger, not sure it's part of the carbs. It was just sitting underneath the right side of the carb on the bike when I was trying to install the carbs back on.

Still left scratching my head I have no idea where it belongs.

[TheGreenWeenie]

Hey man, welcome aboard. I'm pretty new here as well. so i just had to order new o rings for my carbs because they were actually missing from this part


http://i205.photobucket.com/albums/bb17/ben_2_go/Motorcycle%20Stuff/Mikuni%20BST33SS%20Carbs/carbtopvacuumport-1.jpg

these little guys are super important for running right. they should be accessable as soon as you open the top of the carb. the black plastic cap with the slide spring attached.

[TheGreenWeenie]

It's much larger, not sure it's part of the carbs. It was just sitting underneath the right side of the carb on the bike when I was trying to install the carbs back on.

Still left scratching my head I have no idea where it belongs.

disreguard my last comment. I didn't even see your size dimensions. -_-

[lucas]

I don't know of any place on this bike where an oring of that size is used.

Can't guess where it came from.   Was it stuck on with dried oil?  Could you have dropped it on your bike?

[ShowBizWolf]

Welcome to the site pakuna!!!

I don't have any idea either  Buddha where are youuuu do you have any ideas?

...also wanted to say I'm glad you have been enjoying the forum. Good luck !

[The Buddha]

Holy gigantic pics Batman.
Looks like one of those high bypass Turbo fan's built by pratt and whitney for the 747 (I think) isn't it.

Never mind, it is smaller than a penny and its the float seat and the float needle is installed in it - the aluminum part of the left with the wire hook part.

You need that O ring, it is needed to keep fuel from getting into the bowl when the float is closed.

Cool.
Buddha.

[bombsquad83]

If you are having trouble with fuel overflowing into the air filter, then it's due to your float needles.  They are either dirty, worn, or the float height is not set properly with the little tab on the float.  If you haven't replaced the float needle valve sets with brand new OEM parts, I would recommend doing that.  It's not the cheapest, but it's the most reliable fix.  When you get the new needle valve sets installed (it will come with the needle valve, the needle valve seat, and the o-ring for the seat), then double check the float heights.  Do a forum search on how to do this.

As far as the bigger o-ring you found...could that be the o-ring that is supposed to go between the head and the intake boot?  Did you remove the intake boots from the head at some point?   If so, then I'm surprised you aren't having more issues than you are with your idle.

[pakuna]

As far as the bigger o-ring you found...could that be the o-ring that is supposed to go between the head and the intake boot?  Did you remove the intake boots from the head at some point?   If so, then I'm surprised you aren't having more issues than you are with your idle.

Haven't removed the intake boot, the Oring was very clean when I found it.
I'll have a look again between the intake boot & the carb, the oring looked a little small to fit anywhere there though.

If you haven't replaced the float needle valve sets with brand new OEM parts, I would recommend doing that.

Did actually replace the float needle on my problem carb since the rubber on the tip was starting to wear (don't think it was OEM though).

I'm sure the floats are working well, checked them multiple times. The float height should also be set correctly at 13mm. I've cleaned the jets & the carbs as well, but interestingly I noticed some dirt on upper side of the float container/bowl the second time when I took it apart again after cleaning it. Could dirt be getting into the carb somehow and blocking the jets?

You need that O ring, it is needed to keep fuel from getting into the bowl when the float is closed.

Definitely have this bit I've checked about 3 times. 

Thanks for the replies (& welcomes) I'll take another crack at this & take it to the shop if I'm still stuck.

[lucas]

I'm going to go ahead and conclude that your bike was contaminated with a foreign oring.  That size oring (  34mm outer 24mm inner & 3.5mm thickness  ) doesn't appear anywhere on the GS500.

[sledge]

You wont find a 34x24x3.5mm O-ring anywhere on a GS5....in fact you wont find one anywhere...PERIOD!!


If it has an OD of 34 and an ID of 24 it MUST be 5mm section.


Have the fork tops been off recently? There is an O-ring, underneath them that's approx. that size.

[pakuna]

My bad there's a bit of a typo. It's supposed to be 34mm Outer 27mm inner and 3.5mm thickness.

Haven't touched the forks at all.