Gas just POURS out of the YICS port

Hey guys,

I got my stuff together, I undid one bolt on the RHS (facing forward) of the YICS port, undid the LHS bolt, and gas just POURed out of it. I thought I'd just let it pour out, but a hefty amount came out... So I guess it's feeding from the gas tank? Is this normal?

Edit:
TBH it looks like old, oily gas, but I'm not a good judge of colour or gas age. Could very well be the brand new gas from the tank...


-Matt

 

That doesn't seem right .... and if it IS coming from the tank somehow, that indicates not only a failing petcock vacuum valve, but also sticking float valves that don't stop the fuel flow when the bowls fill up.

Unless your petcock is on prime? Then that would point to just the float valves...

I would say that isn't normal and would mean that you need to do some work on your carbs. If there's gas coming out of there, I'd even venture to say you probably have gas in your oil as well.

 

YICS ports are "intake air" booster ports and gas should not be pouring out under any normal circumstances. Switch is right, and be sure you check for gas in the oil before you start the motor and do some serious damage.

 

Well, I suppose I can add a bit to the story. I just had the carb.s off to clean them, valves etc. I did have the petcock on prime, and I am sure that at least 2 of the 4 float valves are not sticking (I didn't specifically measure the float 'tube-test' height in the other 2, but they are set to very similar levels a.la 17.5mm. Moreover, before I took my carbs off, the floats were set very high (so MUCH gas would get into the bowls, much less than 17.5mm from the base, upside down).

I will check the other 2 and report back. Looks like I'm not out in the clear yet =/

 

Yea I have now finished checking (and re-checking) all 4 float valves. They stop for sure. With such a short time, it's possible they leak SLIGHTLY, but they all 'stop' at ~3mm below the float bowl height.

At any rate, I've gotta go back to university. I left the bike on prime, so if the floats leak, I'm gonna smell / see it when I get back. They didn't leak in the past (before cleaning) and I doubt I wrecked them. So we'll see.

Thanks!

-Matt

 

Not uncommon for the float or needle to stick when reassembling on bike. You could have had that issue but is cleared up now. Give it another check when you get back. You may want to remove the plugs and rotate teh engine a bit to make sure you don't have a lot of gas in the cylinders as well as checking the oil as fitz said.

 

Yea I'm going to check the oil for sure, I might just change it to be safe, why not? I did have the valve cover off, etc. WHATEVER.

So, what I should do is rotate the engine (with it on prime?) Then try to pull out the YICS bolt? If the float/needle stuck open, would the tube test not fail?

I could just shove the tool in, I am sure it would stop the gas...

Thanks again,

-Matt

 

I figure your needle not stuck now - does gas still come out? If it is I'm not sure how you would avoid seeing a high level using the tube.

You want to turn the engine without plugs to dislodge any gas in the cyls after you resolve the flooding.

 

If gas has quit going everywhere, pull the fuel line with the petcock off and make sure it's OFF. The way I've done it is to clean up the area thoroughly and discard that rag, and then wad up a perfectly clean shop towel around the petcock and come back in a couple of hours and "check the diaper." Then, if still dry, go ahead and reconnect the fuel line and put it on "PRI." Pull your YICS plugs (I'd pull both ends) and be sure no fuel is going down the intakes. If the float needles are working correctly, you should observe nothing out of the ordinary. I think Bill is right, you HAD a stuck float needle that quit sticking as soon as it got "cycled" a couple of times while in its fuel bath. Or a minute piece of crud that dislodged itself. You ARE running an in-line fuel filter, aren't you? Make sure you leave the petcock in the "on" position while the bike is sitting.

 

In the past there was no inline fuel filter, but there is now. I will try to see what happens.

Expect updates, thanks again guys.

-Matt