Gas leak from left rear carb

[al v]

Would like to confirm or rule out possible hydrolock potential...

Went into the garage today and it smelled of gas. I found a couple of drops of gas under the left side carbs. The photo above is of the left rear carb, you can see there is a drop of gas hanging straight down from what I believe is the pilot screw (correct me if I'm wrong, I'm still new on the valkyrie)

There also appears to be gas leaking around the screw just to the right of that.

The gas was turned off. I have an OEM petcock. (I do understand that off doesn't necessarily mean off)

I recently took the gas tank off to change the air filter. When I did that I had found that the previous owner had not drained the air box drain and it was filled to just under the air box. I drained the tube and replaced the oil soaked air filter. Other than that, no other changes have been made under the gas tank.

As a precaution, I have pulled the spark plug out. I have not tried to start it... I have wiped off the gas and I'm currently waiting to see if and where a fresh drip will show up.

Thoughts?

[GOOSE]

The screw that you are looking at is the carb bowl drain screw....To drain the carb bowls, you loosen these screws, and the gas will drain out of the hose you see to the right of the screw, and out underneath the bike.  That drain screw, and the other 5 each have an o-ring on them.   an o-ring could be bad, or cracked, which could cause the leak.  You need to test the oem petcock, and determine whether or not the diaphram in the petcock is bad, and repair or replace it.  If the drain screw o-ring is good, go to the petcock...if it needs to be repaired...fix it...if you have to fix the petcock, then you may have to pull the carbs to check the bowls for crap in them, and to check the floats/needles.

[Bone]

I would pull all of the plugs. Maybe I'm over-cautious.

[sugerbear]

1st off,  nice picture, it helps alot.

the obvious screw you see is the bowl drain. could be leaking a little.
 vertical point to the left is the idle screw(points down. uses a "d" socket to turn)
tube to the right is the bowl drain tube.

if it wasn't leaking before you took off the tank, start there.
make sure the fuel line is secure to the tank and not split or loose.
try tightening the bowl drain screw(i don't think that's it though)
dry everything off and look again the next day.
let us know what you find.  

damn goose beat me to it.  LOL

[Michvalk]

Before you do anything else.....Check to see if the screw is tight

[Mr.BubblesVRCCDS0008]

Easy way to check  for hydro before tearing into anything is the put the bike in 2nd or 3rd, key off pull the clutch in  roll it a little and let the clutch out. If it is hydrolocked the rear tire will just skid and nothing will be damaged. If it turns over no lock has occurred.

[al v]

I checked the bowl drain screw and it was tight. I opened it slightly, confirmed gas draining out and tightened it again.

I cleaned everything up a couple of hours ago and everything is still dry. I'll wait for tomorrow and check again for any leaking...

I last rode the bike on Saturday, so it had been sitting for three days before I found the problem. I had noticed a slight gas smell yesterday and dismissed it so that was two days.

If it comes to restarting the bike, what is the best way to absolutely rule out gas in the cylinders? Should I try pulling all the plugs and try pushing the bike in gear?

[Attic Rat]

Pull the plugs and spin the engine over if gas comes out then there is gas in the cyclinders if no gas comes out then there isn't any gas in the cyclinders very simple

[John U.]

It won't hurt to spin the starter with the plugs removed but the gas (if a cylinder is full) will blast out and create a fire/explosion hazzard. Don't do this in your garage.
It's a good idea to tape the plug wire boots to avoid an ignition source.

[threerides]

You could check the oil and see if the level is correct and if it smells like gas.  Jim

[whitestroke]

You could stick   pipecleaner/?   in plug hole, to check for gas.  To make sure there won't be a fire danger.

[al v]

I have confirmed that the bowl drain screw on the rear carb on the left side is diffidently leaking even though the screw is tight. It's been about 7 hours and there is now a single drop, so the leak is pretty slow.

I took the screw all the way out. The gas that drained out looked clean. The o-ring looks to be good as new. The tip of the screw where it seats had some discoloration and just a hint of a gray buildup that was creating an edge I could feel by running my thumbnail over it. The threads were great, nothing cross threaded. I used some super fine 600 grit sandpaper and ever so lightly polished the rough spot off and reassembled.

I then tested for hydrolock by putting the bike in 4th gear and rolled it forward through a dozen or so strokes. It's a beast to push, but it turned over just fine. (That's one less thing to worry about)

I then started the bike and ran it for a few minutes to refill the carbs with gas.

I'll check again tomorrow to see if the leak has been corrected. If not, I might have to order some new screws. (Hopefully the seat in the carb body isn't the problem.)

No leaks yet from the idle screw.

[al v]

Thanks everyone for the suggestions so far! This board is a huge help to someone like me that just purchased their first valk only recently. My bike is a 98 and only has 9600 miles on it. I purchased the bike in November and other than a few short rides, I've had to patiently look at it all winter. I'm the third owner. The second owner only had the bike for one summer and had completely detailed it from one end to the other. It was love at first sight when I saw it. I had my heart set on a burgundy tourer and I feel very lucky to have found one in such good condition. When I got the bike it was just about completely stock. I've spent the winter customizing the bike. I was reading on the site recently about how many "valkaholics" there are... It might be possible that I'm coming down with the same condition. Thanks to the resources on this board, it's possible for a guy like me to make sure my valk lives a long healthy life.

[al v]

You could stick   pipecleaner/?   in plug hole, to check for gas.  To make sure there won't be a fire danger.

I would not of thought of pipe cleaner. That would be a great way to check as well. It would definitely require a lot less muscle compared to pushing in gear.

[sugerbear]

"I'll check again tomorrow to see if the leak has been corrected. If not, I might have to order some new screws. (Hopefully the seat in the carb body isn't the problem.)"

new screws won't fix it. if it's leaking at the bowl and the screw is tight, you need bowl gaskets.

just rebuilt my buddies carbs using the redeye kit. also bought new screws for all the carbs(just in case) original ones are kinda soft. you might be able to replace the gasket with the carbs on the bike, i've never tried it.

[GOOSE]

al v  .....If memory serves me right, you cannot buy just the float bowl drain screws without buying the whole dang float bowl assembly.  If it is leaking out from around the drain screw, then I would buy new o-rings for the drain screws.....o-ring (size:  1.3mm x 4.3mm) honda #:  16075-GHB-640.  When you tightem up the drain screw, remember that you are tightening the screw into an aluminum/soft metal, so don't go crazy, and overtighten it.....the o-ring is what is going to be making the seal for you.

[al v]

Cleaning/polishing the drain screw seems to have solved one leak. That's good news.

The bad news is that there is still gas leaking from the idle screw. The hole for the idle screw is slowly filling up.

I ordered the idle screw tool and o-rings from redeye tech. (along with the quick disconnect for the gas tank, what a great idea that is)

Is it possible to replace the idle screw o-ring with the carb still on the bike?

[Ricky-D]

The O-ring on the drain screw is placed there to insure the gasoline goes into the drain line barb rather than running out along the screw itself when loosened to let some gas drain out.

The O-ring has no ability to stop gasoline from leaking when the screw is tightened down. That is the job of the screw tip.

***

[whitestroke]

Idle screws/Pilot screws
Yes, you can replace o-ring with carbs on bike.
Be very carefull parts are small. there's a spring, washer and o-ring and any one of them can stick up in the hole. Whatever you do don't lose washer or spring.  I used a small piece of wire and bent a tiny hook on the wire to pull out oring and washer.