Odd fuel leak

[AZdougness]

Hi there VRCC tech gurus,

I found a very odd fuel leak two days ago when I was running low on fuel in preparation for removing the tank this week. When I was still warming up the bike she started dogging and I switched the petcock over to the reserve tank. Within seconds there was gasoline coming out of the air vent hose on the left side carb bank (bike was leaning left on the kickstand) and draining directly onto the top of the engine block, as well as the bikes left side exhaust shot out some white looking smoke. I understand that these two lines are to help equalize pressure with a diaphragm inside the carburetor and when blocked with gas they can cause hydrolock by pressurizing the carb bowl chamber and pushing gas out of the slow jets into the manifold. Obviously this is something that I do not want to happen. I kept the bike running and switched back and forth between the two positions on the petcock, each time the reserve setting made more gas leak. I leaned her up, put her in gear and while rolling down the road I switched to reserve and the issue stopped.

Has anybody seen this before? I tried searching the forum and I didn't come up with any results, unfortunately air vent hose and gas leak turn up a great deal of results, none aimed after this. I just don't understand what turning to reserve would have to do with anything, it shouldn't change the fuel amount getting inside the carburetor body as that is dictated by the floats and valves, and still goes down the same tube fuel normally does. Is there a vent hose or vacuum hose I am not taking into consideration? I am cleaning the carburetors at the moment so now would be an opportune time if there is another needed repair.

Thanks for any help!

As always, worthless without pics.

[Ricky-D]

Could be you were experiencing a sticky float in one of the left side carburetors.

This would explain both of the symptoms.

Neither are directly related to the fuel petcock, except to the possibility that you were veritably "out of gas" and needed to go on reserve, which then supplied the needed gas,,, To reveal the sticky float.

***

[Thunderbolt]

I agree with what Ricky-D said.  Before you re-install the carb bank, set up a temporary fuel supply to the carbs on a work bench outside where there will be no fumes to ignite.  Make sure that the problem does not occur again.  Put the carb drain lines on and put a catch can underneath the common drain line and open and close each carb drain to make sure the floats are working as they should.

[BlueValk]

I agree, also with the above.  I'd like to add that while going down the road, you were possibly using enough fuel to compensate for the small leak.  You might find that if you rev the engine some while stationary, it also may stop the overflowing.
BlueValk

[Denny47]

I don't believe the pic of the carbs were his, I believe the pic is one from Oklahoma_Valk used in another post.

[Oklahoma_Valk]

I don't believe the pic of the carbs were his, I believe the pic is one from Oklahoma_Valk used in another post.

Correct. however, I dont mind if others use my pics. Just make sure to cite the photo, if need be.

In response to the OP, I had the same problem on a set of carbs not long ago. i do not know exactly what caused this leak to happen, but I DO know it was responsible for hydrolocking the bike, and breaking the starter gears etc.

Definitely don't run the bike , or attempt to start the bike until you have resolved the leak. The carbs will need to be removed, and cleaned/inspected. There are lots of posts on the forum about how to do that.

okie

[FryeVRCCDS0067]

I agree, stuck float. Running the tank low might have pulled some crap out of it. But, whatever caused it, you're lucky to spot it that way instead of after your starter gear got broken. Fixed my son's Valk last spring with seafoam when he had a stuck float.

[AZdougness]

I don't believe the pic of the carbs were his, I believe the pic is one from Oklahoma_Valk used in another post.

Correct. however, I dont mind if others use my pics. Just make sure to cite the photo, if need be.

In response to the OP, I had the same problem on a set of carbs not long ago. i do not know exactly what caused this leak to happen, but I DO know it was responsible for hydrolocking the bike, and breaking the starter gears etc.

Definitely don't run the bike , or attempt to start the bike until you have resolved the leak. The carbs will need to be removed, and cleaned/inspected. There are lots of posts on the forum about how to do that.

okie

Your thread, and picture, was definitely helpful in making sure I was tracking the problem to the right place Oklahoma_Valk so thank you already, and to everyone else as well adding advice.

I currently have the carb bank pulled and it is sitting in pieces on my kitchen counter. I have noticed several floats that were not smoothly moving up and down, all of which are getting a nice soak in laquer thinner at the moment. I will post some pics of the job when I get home form work so everyone can see how useful a kitchen counter can really be.

Cheers
Doug

[Oklahoma_Valk]

awesome!

however, some chemicals (I am not sure if laquer thinner is included) Will ruin the rubber components, including the rubber tips on the ends of those float valves. Those float valves are expensive, but if some of them are defective you would be best to order new ones. Order from HDL Parts or your local honda dealership. Try to avoid contacting "carburetor cleaner" of any kind with your rubber parts.

hope you get it figured out!!

Okie

[AZdougness]

Correct! lacquer thinner is most definitely a solvent and will eat away rubber, silicon, and other gasketing materials. Only the strictly metal parts were given a bath.

I wish I had a garage to work in, but my covered parking will have to suffice.


After the first rinse of carb cleaner they are starting to look pretty good! Still a little varnish on some pieces, but nothing a q-tip and cleaner can't quickly remedy!


Yes I have OCD, and yes I want every piece going back in the exact way they came out... haha

[Oklahoma_Valk]

Looks awesome. Pay special attention to those float valves. Make sure they are smooth as a baby's ass. The drays shop video series on YouTube helped me clean mine the first time I did a bank. Looks like you know what your doing though! Rock on.

[custom1]

That's about the time the cat jumps up on the counter and starts batting stuff around. 

Good job though.

I hope I never have to do mine.

[Brian]

WOW. I would call this just being well organized not OCD. Did you seperate the carbs to replace all the other o-rings? The first time I did this I too ignored the fuel rail. About six months later I had to go back and do it.