Gas leaking out of one of the carb vent tubes. Doesn't look like any float issues.

Found the problem with mine, I believe.

20180502_170926.jpg

Aside from the float levels being too high now, which I'm going to attribute to time and needle/seat wear, it appears that the bowl gasket on #3 was interfering with the float, keeping it from closing the needle.

Replacing gaskets and needle/seat assemblies and will reset everything.

In the meantime, I'll research here to see about the appropriate float levels for the Stage 3 Dynojet kit to see if it varies from the factory 22.4mm +/- 1.0mm.

Did you ever find a resolution for this??

I got my bike back up and running yesterday, after repairing some damage after dumping it on it's left side leaving a stop-sign about a month ago, and doing a valve adjustment.

I decided to re-jet it down a size leaner as well (it's been a tick rich for the last 12,000 miles or so) as well.

When I got it started yesterday, I found that fuel was POURING out of the T-Vent between #3 and #4. Petcock is fine, and the floats for at least the #4 carb, which were all brand new with the rebuild of the Carbs about 5-years ago, still floats fine.

Looking at the Needle, which were also replaced during the rebuild, there does appear to be a slight "grooving" where it rests in the seat.

I've ordered a new set (4) of genuine Mikuni Needle/Seat assemblies after reading through all these threads. They are spendy ($31.95 each), but I felt that the K&S units, which I believe are what are in there now, maybe aren't the quality that the originals are, so I popped the $$$ for the real thing.

I feel this is the most likely cause at this point. Another clue was that the float bowl on #4 seemed over-full when I removed it, and compared it to the #3 bowl when I removed that one.

Hey, so this started happening again :/

In addition, the petcock seems to leak when set on prime. Maybe it was a petcock issue all this time.

I' thinking about replacing the petcock. Is OEM the way to go?

edit: Yikes, a petcock looks to be $100. Gonna have to wait until next month to get that :P

Gonna check the floats again, but like last time I doubt there will be anything that looks wrong.

[Rijko]

i toned down my post BigD .. sounded too much like ranting or meddling
which is absolutely not what i meant to do.
My apologies also, i should have PMed you.
Back to topic, you're right. Sorry OP.

[BigD_83]

I get it, but it is what we have here, and many new (er) users aren't aware of how to post in that manner.

Note that we have zero advertising, so the site isn't monetizing itself.

Maybe it's a question that can be thrown to Frank, the site administrator, to see if the funding is there.


...and steering us back to topic. My apologies to the OP for bumping us off course.

[Rijko]

Hi BigD,

thanks !

The disadvantage of external hosting of piccies is that whenever someone
deletes their account, moves some pictures in subdirectories, or a site
like Imgur decides to change policies or even stops ... all mean that pictures
disappear from posts.

edit : removed unnecessary info

Have you noticed the number of unavailable pictures on GSR and other forums ?
I think that way a load of valuable posts are depreciated, which is why i try to
store pics on sites themselves.

thanks for your advice though, i appreciate it !

Rijk

[BigD_83]

Since GSR only allows 1 pic per post i will have to post more than 1 answer

You can have up to 10 images/post by using links to an image-hosting program like IMGUR, Photobucket, etc...

like Hillsy said .... the o-ring is important too.

here's another pic, the copper part is the seat.
Yours may look a little different but you get the idea.
Since GSR only allows 1 pic per post i will have to post more than 1 answer

[ATTACH=CONFIG]50676[/ATTACH]

Thanks for all the images, they are super helpful!

Thanks for the help guys. I'll take a look at these suggestions, and check the o rings to be sure.

[hannibal]

VM26 with screw in seats here. I forgot to tighten a valve seat and that (obviously) led to a leaky carb.

A clear bowl is brilliant!

[Rijko]

From memory all the GS float valve seats are press in (not screw in).

the CV series has the pressed seats, the VM series are the screwed type afaik.
VM 26mm, 27mm, 28mm, 29mm have them

If you're lucky, you can find transparent float bowls and see what's going on

s-l1600.jpg


sometimes the needles have a bit of damage on the sides and
polishing that away solves the issue

[hillsy]

From memory all the GS float valve seats are press in (not screw in). Be careful pulling them out as you can easily distort / fubar the seat where the valve enters. If you squeeze them out of round the valves can stick. A squirt of WD40 or similar will help loosen the o ring.

Anyway, drain the carbs, take them off, take off the bowls, hold the carbs upside down, get a longer piece of fuel hose on there and blow into it. If the valves or seats are leaking you will be able to blow air through them and hear where it is leaking from.

ALWAYS bench test your carbs for leaks before you put them back on.

[Rijko]

10.jpg

sometimes the needle point has little visible wear, but sticks to the copper
seat on the long side of the needle, not the tip.

The issue is worse with bio-ethanol added to the fuel, leaning the mixture
and creating more friction between needle and seat

I have always had succes with this issue by replacing the needles
and seat as a pair.

[Rijko]

sometimes you can see wear on the needle

wornneedle.jpg

[Rijko]

What is the float seat exactly?

Like I said, I checked my needles and they seem fine. Do you know what the characteristics of a good one is, or how can I tell if one is bad?

like Hillsy said .... the o-ring is important too.

here's another pic, the copper part is the seat.
Yours may look a little different but you get the idea.
Since GSR only allows 1 pic per post i will have to post more than 1 answer

mikuni-needle-valve-with-viton-tip-for-spigot-flange-mount-carburetors.jpg