info about my bike:
150/40 jet, straight pipe

recently my bike is acting weird, ideal speed is up to 4000 and won't go down, but if I apply to neutral at high RPM, it would just go down to below 1k and died.....

One day I decide to check the carb, after putting it back, I found the carb is leaking over the air vent hose and the carb body, I took the needle valve and float and clean them, same problem.

Check out the pics below, they looks fine to me......so in the end I have to replace the floats and valve needles?

They look fine, but there is another place to check. Pull those brass tubes that the needles sit in. see if the o-rings are good. I would bet they are hard, flat, and maybe cracked.

Quote from: Paulcet on May 20, 2011, 04:04:55 AM
They look fine, but there is another place to check. Pull those brass tubes that the needles sit in. see if the o-rings are good. I would bet they are hard, flat, and maybe cracked.

forget to mentioned....I did change the orings in the brass tubes....they are good....so any other guess?

Get the Utube out and do a float level test. I'll bet your floats are sticking open.
Over the top leak = for sure stuck floats.
Cool.
Buddha.

Quote from: The Buddha on May 20, 2011, 10:24:17 AM
Get the Utube out and do a float level test. I'll bet your floats are sticking open.
Over the top leak = for sure stuck floats.
Cool.
Buddha.

Yes, I did test it.....well it looks all good offborad, so put the carb back on the bike, then it starts to leak......I took them out again and could not figure out what is the problem....

Either one of your needles or seats are worn,your float level is incorrect,or one of your floats has a hole/crack in it.These are the only things that will has a carb to flood out of the vent tube if the O rings were replaced with the correct size.Please check this link to see exactly where your fuel level is at. http://gstwin.com/float_height_check.htm

Quote from: ben2go on May 20, 2011, 06:21:54 PM
Either one of your needles or seats are worn,your float level is incorrect,or one of your floats has a hole/crack in it.These are the only things that will has a carb to flood out of the vent tube if the O rings were replaced with the correct size.Please check this link to see exactly where your fuel level is at. http://gstwin.com/float_height_check.htm

thanks for ur tips, my float level looks about 1/2 inch lower than the gasket that separates the float bowl from the upper half of the carburetor body, other than that, my last pics shows that there are marks(or should I say steps) on the needle valves, do they made that way or worn that way?

Quote from: hhlragnarok on May 20, 2011, 07:27:07 PM

Quote from: ben2go on May 20, 2011, 06:21:54 PM
Either one of your needles or seats are worn,your float level is incorrect,or one of your floats has a hole/crack in it.These are the only things that will has a carb to flood out of the vent tube if the O rings were replaced with the correct size.Please check this link to see exactly where your fuel level is at. http://gstwin.com/float_height_check.htm

thanks for ur tips, my float level looks about 1/2 inch lower than the gasket that separates the float bowl from the upper half of the carburetor body, other than that, my last pics shows that there are marks(or should I say steps) on the needle valves, do they made that way or worn that way?

Ahhh I see what you speak of.I have four GS500 bikes,and none of their carbs have that step like yours.My bikes are 89,90,91,92 year models.I don't know if any other years have those needles like that.I am think that the needles are worn and occasionally sticking open as you described.I would replace the needles and seats.

Quote from: ben2go on May 20, 2011, 08:04:12 PM

Quote from: hhlragnarok on May 20, 2011, 07:27:07 PM

Quote from: ben2go on May 20, 2011, 06:21:54 PM
Either one of your needles or seats are worn,your float level is incorrect,or one of your floats has a hole/crack in it.These are the only things that will has a carb to flood out of the vent tube if the O rings were replaced with the correct size.Please check this link to see exactly where your fuel level is at. http://gstwin.com/float_height_check.htm

thanks for ur tips, my float level looks about 1/2 inch lower than the gasket that separates the float bowl from the upper half of the carburetor body, other than that, my last pics shows that there are marks(or should I say steps) on the needle valves, do they made that way or worn that way?

Ahhh I see what you speak of.I have four GS500 bikes,and none of their carbs have that step like yours.My bikes are 89,90,91,92 year models.I don't know if any other years have those needles like that.I am think that the needles are worn and occasionally sticking open as you described.I would replace the needles and seats.

So I get back to the method that the manual mentioned to check the float height, looks like mine are out of range some how, so I bend the tongues to get them back to tolerance.....then I lost one of the little hook on needle valve....u are right, I have to replace them now....haha

and the needle is hard to find and expensive, anybody has them as spare parts?

http://www.oldbikebarn.com/Suzuki-GS500-GSX1000-Carb-Repair-Kit?sc=12&category=73881

http://www.partsnmore.com/parts/suzuki/gs500/?filters[category]=carb  Scroll down a little on this site.

Quote from: ben2go on May 21, 2011, 06:24:40 AM
http://www.oldbikebarn.com/Suzuki-GS500-GSX1000-Carb-Repair-Kit?sc=12&category=73881

http://www.partsnmore.com/parts/suzuki/gs500/?filters[category]=carb  Scroll down a little on this site.

Thanks....I've ordered them, now let's wait......

I took a test ride on my bike today and I think my bike needs needles and seats.My left one seemed to be hanging shut.