Carbs leaking after new needles/seats

[kartin]

1979 GS1000E. Put in new float needles and seats (not OEM) and set float height to 24mm. More than 1 carb overflowing like crazy. Checked everything clean, re-checked float heights and checked floats free to pivot but still leaks. I think it could be:
- new needles/seats were poor quality (but they look fine to the eye and needle springs operate freely)
- floats have gone porous (does that happen to the solid type?)
- seat sealing washers don't (seal)
- maybe I didn't set the height correctly (I inverted carbs and measured from gasket (still in place) to bottom of float as 23mm. Then added 1mm for the gasket thickness.)

Any other possibilities? And how to figure out which of these? Thanks...

[Dave8338]

Did you float the floats in fuel prior to reinstalling them? Where on the carbs, is the fuel coming from? When you say bottom of the floats (for your height measurement) where did you actually measure from? Did you make sure that the petcock is working correctly?

[khardrunner14]

Check this out...it was helpful for me.

http://www.thegsresources.com/_forum/showthread.php?t=104807&page=3

[kartin]

To answer the questions:
- Fuel is coming from the overflow outlets on the bottom of the float bowls.
- I measured to the most distant part of the circular float (my floats are not quite like the picture - more like a complete circle in profile)
- no, didn't check for floatation (I assumed that test only applied to hollow type floats - my bad)
- my petcock is non-vacuum so either fuel is on (and carbs leak) or off (and they don't)

I think my next steps are:
- drain fuel from #4 bowl
- remove bowl and float
- check float floats
- reinstall float
- hold float up by hand
- turn on fuel
- see if it leaks like that and where coming from
- if I can control fuel flow like that, I'll try the "clear tube" fuel height method

[Dave8338]

That would be my next step. See if the needle/seat combo is doing it's job, if so, the next thing would be the floats themselves. In theory, the seats should hold the pressure of the fuel no matter what level it is in the tank, I've had toys where this didn't work, no matter what I did.

[spchips]

many needle/seats/needle valve, or whatever it's called, in rebuild kits are complete garbage. If they seal at all, the height's often wrong. If the old ones aren't shot, don't get rid of them.

Suzuki parts might be worth a shot, although it'll probably hurt in the wallet.

[rphillips]

I reckon you did use new "O" rings. Na, even old "O" rings wouldn't leak that bad.

[kartin]

Yes, cycleorings kit installed but I don't think there are are any o-rings controlling fuel fill/overflow - right?

I do still have the original needles and seats - or at least whatever was in there since don't know if the PO changed them - I changed to the new ones "just in case" but will try one of the old ones tonight...

[rphillips]

I think there should an "O" ring on each seat, that keeps the fuel from going thru the small space between the seat & the carb.

[robertbarr]

I think there should an "O" ring on each seat, that keeps the fuel from going thru the small space between the seat & the carb.

On a CV, yes. Not on the VM's.

[ptm]

I had a problem with one bowl overflowing after a rebuild. I'd take them off and everything looked fine. I'd put them back on and a different one would overflow. I finally thought that maybe the float/needle/seat was getting cocked with all the gyrations I did to get them back on the bike so I took a plastic screwdriver handle and lightly tapped on the offending carb bowl. That was enough to get it uncocked and moving up and down properly so it could seat the valve. I've had no problems since - 8,000 miles and counting.

It's easy to try and it's easy to tell if it works.

[rphillips]

There I go, wrong again. I was thinking the "79" 1000 "E", had CV carbs & electronic ign. but after a pic or 2 I they don't. sorry

[49er]

Check the new needle valves and seats against the old ones for length of needle. Make sure that the new needles seat at the same hight as the old ones. Also check that there is an ali or fibre seal fitted to the seat assy. This seal fits between the seat and the carb body. If it is missing, the needle hight will be incorrect and may cause the bowl to flood.
Apart from checking that the floats aren't leaking (won't float), you could check that the float assys aren't contacting the sides of the bowl or anything inside the bowl causing them to stick down.
Apart from ptm's sticking valve experience, or excess fuel pressure (not an issue with gravity feed), there should be no other reason for your VM carbs to flood.