Leaky carbs

[Guest]

A friend if mine was complaining of leaking carbs on his 1980 GS850G. I pulled the rail and took the bowls off. I cleaned it out a bit and blew out some passages. Still leaked, like a civ. it's just 3 and 4. I didnt see anything wrong, or abnormal. Anyone have any ideas why they would still be leaking??

[cowboyup3371]

Did you do a proper rebuild with new orings and such? If not, I'll bet your orings are bad and the floats weren't properly set. Not to mention how's the petcock?

[andtheacademics]

Did you do a proper rebuild with new orings and such? If not, I'll bet your orings are bad and the floats weren't properly set. Not to mention how's the petcock?

I just went through this whole debacle about a week ago, gotta pull em - check the float needle valve and float needle valve seat. Mine were a tad marked but didn't really have a shoulder on them yet.

Then adjust your float height! All of my floats were at least 5mm off spec allowing way too much fuel in the bowls. This can be a pain because you may end up bending the tab, reassembling, measuring, not enough, pull float hinge again, bend tab, reassemble and on and on. Anywho, it payed off.

If the carbs are leaking steadily with the bike off - especially if it seems like more fuel than four float bowls can hold - AND if you are running a vacuum petcock then I would be willing to bet there is an issue with that bad boy.

(I only learned all this stuff recently so it's fresh to me!)

#3 was leaking big time for me too - it had the most offset float height of all of the carbs, and (I'm not sure if this is relevant to leaking seems to be the "master" carb on most of these bikes...

[Nessism]

Throw a band aid on them if you want, but you will be back into them in short order if you do.

Best bet is to fix the carbs right one, or in your case, the second time. Carb rebuild tutorial is linked in my signature. Also, check out the Newbie Mistakes thread.

Good luck

[Dreef1999]

have you tried tapping the side of the carbs with a mallet while right side up? Sometimes the parts just need to settle into the right orientation.

Of course if you half assed the rebuild you should do that regardless.

[MunkyMastr]

Well, I will say, I did not rebuild them. I just pulled them apart and checked them out. I don't have any parts to rebuild them properly at this point. The petcock drips a little even when off, and it is no a vacuum petcock. I tried tapping them, but no luck. Seems I just need to rebuild them the right way, which I figured. Thanks all!

[AlTheKiller]

I'm having a similar issue with my #2 carb. I rebuilt them and jetted using the Dynojet kit. After running the bike, then setting it on the side kick stand a little while later i would have some gas drip out the air filter and some out the vent tube between #3 and #4 carb. It doesn't continue to do it, just a bit then it'll stop. I pulled off the carbs, adjusted the float heights (all of the carbs) a bit and also replaced the needle seat, needle and needle seat o-ring in the #2 carb as the needle was sticking a little.

So after all this last night I was informed that after running the bike and pulling it into the shop to keep it from getting rained on, that specific carb was dripping some gas again after I had left but it's no longer leaking out the vent tube.

What else should I check or adjust? Current float height is at ~23.5

[tom203]

I don't have any parts to rebuild them properly at this point. The petcock drips a little even when off, and it is no a vacuum petcock. I tried tapping them, but no luck. Seems I just need to rebuild them the right way, which I figured. Thanks all!

Hopefully all you might need (after proper cleaning) is replacement O-rings and gaskets- fuel needle/seats might be worn, but rest of stuff doesn't wear out so avoid "rebuild" kits with inferior parts. visit cycleorings.com for o-ring goodies.

[MisterCinders]

I'm having a similar issue with my #2 carb. I rebuilt them and jetted using the Dynojet kit. After running the bike, then setting it on the side kick stand a little while later i would have some gas drip out the air filter and some out the vent tube between #3 and #4 carb. It doesn't continue to do it, just a bit then it'll stop. I pulled off the carbs, adjusted the float heights (all of the carbs) a bit and also replaced the needle seat, needle and needle seat o-ring in the #2 carb as the needle was sticking a little.

So after all this last night I was informed that after running the bike and pulling it into the shop to keep it from getting rained on, that specific carb was dripping some gas again after I had left but it's no longer leaking out the vent tube.

What else should I check or adjust? Current float height is at ~23.5

Check your oil for any gas smell. If there's gas in there, change the oil and filter before starting the engine again.

Otherwise, make sure that the floats are not sticking, that the needle valve and seat are closing properly, and that there is no other source of fuel bypassing the needle/seat (e.g., a bad washer on the seat).

Also, make sure your petcock is not failing, leaking fuel through the vacuum line, etc.

[AlTheKiller]

Last the first time this happened there wasn't any gas in the oil and I'll check again now.

Could it be that the float is getting saturated and sinking?

I'll check the petcock as well. When I had it off and apart everything seemed great but of course looks can be deceiving.

[MisterCinders]

Last the first time this happened there wasn't any gas in the oil and I'll check again now.

Could it be that the float is getting saturated and sinking?

I'll check the petcock as well. When I had it off and apart everything seemed great but of course looks can be deceiving.

Do you have those hollow brass floats? The solid rubber floats won't sink or soak up fuel.

Floats can snag, however, on the bowl gaskets or sides if they get bent the wrong way. When you check the float height, make sure the float moves easily. When you put the bowl gasket back in place, check the float movement again to make sure it's not rubbing against or catching the gasket.

I had at least one float that had too little clearance from the gasket edge, causing it to stick open and flood the carb.

[AlTheKiller]

They are rubber or plastic floats. When I had it out to replace the needle, seat and o-ring I shook it to see if it filled but there wasn't any noise or feel of liquid in it. Probably cuz they are apparently solid hahaha.

I did also check to make sure there was free movement but it was probably before I put the gasket back on.

[AlTheKiller]

Checked the oil and there does not seem to be any gasoline getting in. The level is normal and it doesn't seem to smell like gas either.

[MunkyMastr]

Thanks for the help, guys. We took the carbs apart again and set the float heights by eye to get it to stop leaking and get him riding. I'll make him do it all the right way soon.