gas leak troubles

I had my carbs off to do a valve shim clearance adjustment, along with a bunch of other irrelevant stuff, and I finished the job, and put the carbs back on, hooked the tank up. New spark plugs, charged battery. My bike was running fine prior to the valve shim adjustment, I just noticed that a lot of the clearances were tight and decided to do it. I figured I would put the carbs back on without rebuilding them to see if they would still be fine. They sat for a while in my garage...

So here's the trouble. I didn't realize it at first, but the petcock was set to PRI when I poured gas in. It almost immediately started leaking out the drain hoses coming from the T joint in between carbs 2 and 3. I realized this and quickly turned the petcock to ON and it stopped. I figured it was just flowing quickly and the carbs were full already... so I tried to start it, and it wouldn't go, it would just spew more gas out of the drain hose while cranking.

I checked the oil fill hole for the smell of gas, and there's no sign of it I think. It smells kind of like an old ash tray or something

So from what I've read on here it seems I have one of three problems:
-leaking petcock
-stuck float valves
-shot o-rings between the carbs

I just tested the petcock by setting it to ON and removing the fuel line from it. No fuel poured out.

So I imagine it's time for a visit to the church?

 

Check for Spark.
Check to see if your Plugs have become "Wet Fouled".
While the Plugs are out, engage the starter and see if Gas spits from the Spark Plugs Holes.
• Install an Aux Shut-off Valve. •

If the Plugs are severely Wet Fouled do a Flashlight check of the level of the Crankcase.
High. Do New Oil and Filter.

If the Holes spit.
Blow Air in the Spark Plug Holes with the Exhaust Valve Open.
Compressed Air or Shop-Vac CLEAN Exhaust.
(Dont vacuum wet holes, ... the Vacuum will catch fire or EXPLODE!!!)

 

FLoats not working properly is a very common problem when carbs have been sitting on a shelf for a while. It looks like your carbs got flooded very quickly because the petcock was on PRIME, but it would have happened anyhow (but more slowly) with petcock on ON.

You would have to wet set your float valves levels carefully, if one of more of them are leaky you will find very quickly, because the level in your test tube won't stop rising.

 

Okay when I'm back at the garage I will try those things Rick.
So the spark plug holes are NOT supposed to spit then? And if they do, and I blow air in the holes, what is that doing?

Quebecois, so you're saying that if it is my float valves, then the gas should be leaking slowly even if the petcock is ON? Because I still have the tank hooked up, and petcock ON and after sitting for a few hours it hasn't leaked at all.

 

While your petcock is not leaking at all, I would have said that your carbs will get flooded any how WITH THE ENGINE RUNNING, of course.

Just to explain with a comparaison, the petcock on my Seca 900 has stayed on PRIME for 3 weeks lately, and I haven't experiment any flooding in the carbs nor in the engine case. Why? Because my floats valvles worked properly. Yours don't seem to do so, obviously.

 

Thanks for the clarification.
Is there a How-To anywhere on here explaining how to un-stick float valves? Or is it just a matter of getting in there and moving them around, and then while I'm at it, completely rebuilding the carbs? I can't seem to find any threads explaining the process.

Also, could running seafoam through the leaking system by keeping it on PRI possibly help?

 

Here is an interesting writing about Seafoam for float valves.
"For the float valves, often it's enough to do a "HARD" SeaFoam treatment or two to clean out the crud that might be causing the valves to stick but just as often it's necessary to remove the carb rack to open the float bowls and service the float valves."

Hard Treatment
• add ½ can of SeaFoam to reserve
volume of gas (3 Litres, ~ ¾ U.S. gallons)

"The HARD treatment is an aggressive method of clearing stubborn carburetor congestion. This is something you might try if your carburetor problems are more pronounced but you just don't want to remove the carbs to do the job right. For a HARD treatment, just add the specified amount of SeaFoam to the specified amount of fuel, then run the bike for 5 to 10 minutes. That should be long enough for treated fuel to get cycled through the entire fuel system. At that stage, park the bike somewhere flat, on the centre stand, and allow it to sit over night to give the SeaFoam time to breakdown whatever it can. In the morning, let the bike idle until it's up to operating temperature (unless your idle is too horrible to speak of), then take it out for a good run at all speeds until the tank is nearly empty (use up the entire 3L of treated fuel while driving). When the tank is nearly empty, fill in only 3L (~ ¾ U.S. gallon) - of fresh fuel, just the reserve volume - then pour in another HARD treatment amount of SeaFoam and again let the bike sit level over night. Repeat the cycle 2 or 3 times, or until you believe you've accompished all you can. In most cases 2 or 3 HARD treatments should suffice but sometimes no amount of SeaFoam can clear the carbs adequately. If you find that there's little or no improvement after a number of treatment cycles, you may have to resort to removing & opening the carbs for a thorough cleaning - sometimes that's just unavoidable. " Harald Pfeiffer, maxim-x.com

I would add that some have had success by tapping the carb bowls with a screwdriver handle to break the sticky fuel valve free.

 

I also remember that someone suggested to use a hand drill with a Q-tip and Autosol to polish the float valve seats for smoother operation. Of course, that means you have to pull the carbs off and open the bowls.

 

Great, thanks.
The bike currently won't start up because of this issue I'm assuming, so I wouldn't be able to do the Hard Treatment just yet, but I will try tapping them and see if that works. If not, I guess I'm pulling them out!

 

Chances are, the carbs have never been serviced. If they have, there's an equally good possibility whoever was in there ahead of you didn't know what they were doing.

Don't assume "rebuild." Pull them off, clean and inspect. Replace the gaskets and o-rings, and other necessary parts. Wet-verify the float levels.

Running a strong dose of SeaFoam through them is not going to reverse 25+ years of neglect.

 

Indeed. Thanks for the advice. Adventure time... hopefully finances will be permitting. I might check out the local salvage yards to see if they have any extra racks that I could get a little practice on.

 

If the Floats are sticking because the Carbs sat and the Fuel dried-out and Varnish was left-behind, ... Seafoam may only complicate matters.

To effectively clean a set of Carbs that did the Rip Van Winkle you have to Pull the Rack and meticulously Clean them, ... including:

Pulling the #1 Carb off-the-rack
Extract the Fuel Gallery "T"
Scrub the Gallery ID and T with a Tube Brush
Clean Beenie Screens
Remove and Clean Main Nozzles (Emulsion Tubes) ID/OD & Tiny Air Orifices

http://www.amazon.com/SMALL-TEST-TUBE-B ... B001DBJL3W

 

Would you please explain why and how Seafoam would complicate matters?

 

Some Carbs are so filthy, ... that Seafoam turns the dried-up fuel residue into a molasses-like substance that clogs everything it comes in contact with.

Seafoam isn't any magic potion.
It's mostly Rubbing Alcohol and Lighter Fluid with some Water added.

 

Once you get the carbs clean and pretty, I would check for debris in the tank. Sounds like your bike ran before, so it sounds what caused the issue was taking off the tank and shaking all that debris loose and thereby sending crud to the carbs. Not saying your carbs don't need be cleaned, but I would also pay attention to the tank so it doesn't happen again. Give it a few good rinses with fuel or mineral spirit if you don't want to mess with fuel. Better with the petcock out and might as well inspect the petcock seals while its out. After you get most of the gunk out of the tank, install an inline gravity clear fuel filter to help avoid any future issues with the float valve/seat.

 

It was about a month and a half that my carbs were on the shelf.
I am planning a total carb rebuild, but I tried hitting the float bowls with a wooden hammer handle, and it must have knocked the floats free, because it stopped leaking gas and was SUPER close to running. I think once it's warm she'll go. But once I know I can afford some rebuild parts I'm going to have at 'er. Cheers fellas!

 

Oh, and thanks for the tank advice. I had a peak in the tank and it wasn't too bad actually, so I didn't bother doing any rinsing or anything, but I did get a new inline fuel filter.