• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

flooding/petcock issue

  • Thread starter Thread starter kevsgs
  • Start date Start date
Hey, like I said, I got the idea from bwringer. My setup/configuration might be a bit different (IDK), but he was the originator. It does work really well, though. I especially like having a cap on the tank. I have seen pics where folk are running their engines with an open container of gasoline connected, and it makes me shudder.
 
Could you specify what you mean by "flooding" or "The float bowls just flood"?

Is your bike running? If so, is it running rich? Is fuel pouring out of the carbies? Is your air cleaner dirty?
S.
 
koolaid_kid said:
Hey, like I said, I got the idea from bwringer. My setup/configuration might be a bit different (IDK), but he was the originator. It does work really well, though. I especially like having a cap on the tank. I have seen pics where folk are running their engines with an open container of gasoline connected, and it makes me shudder.
Click to expand...
That worked out awesome! Here's a pic:
 
silverhorse47 said:
Could you specify what you mean by "flooding" or "The float bowls just flood"?

Is your bike running? If so, is it running rich? Is fuel pouring out of the carbies? Is your air cleaner dirty?
S.
Click to expand...
Well the fuel level rises above the floats and runs out of what I believe is the air ports for the mixture, the holes at the bottom facing towards the airbox. When the needles should be stopping the fuel as the float hits its hieght, they're not and it just floods/flows out of those holes.
 
And yes it runs, I don't run it very long because it overflows while idling, but if I stay on the throttle allowing the fuel to be used up it doesn't flood, and it sounds good. One reason I'm trying so hard to get it fixed is because of how strong the motor sounds while running.
 
Thanks for the clarification. To me 'flooding' is raw gas in the combustion chamber, and 'overflowing' is gas running out of the vents of the carbs. Either way, this sounds like a mystery.

You said you can find a point in the float level adjustment where there is no leakage, but then at only .025" lower the carbs overflow? Is that right? It's hard to imagine how there could be a problem with the float needles or seats if they seal at some point in the adjustment. Could the floats be hanging up on the sides of the float bowls?

I was taught to 'spin' the float needles on the seats by hand, gently, a few times before finalizing installation, just to make sure the seat and needle were mated together properly, ...similar to how you might lap a valve. The idea isn't to grind away at either, but just to give the rubber or metal a chance to seat...especially if you have changed one without changing the other.

I hope new orings solve your problem. It sounds like you have been thorough, but do make sure the floats aren't rubbing on the sides of the fuel bowls. The sad truth is that on the bench the floats can be perfectly adjusted, but once the fuel is pushing up on them, all kinds of slop in the mechanism comes into play, and so you never really know (unless the bike runs like a clock) if the fuel levels are equal across the board.

A sight glass or clear tube attached to the fuel bowl drain plugs tells you exactly where your fuel is inside the bowl, and if your problem persists after you install the new orings...consider making one from an old drain plug. One would 'think' that if all the floats are set at the same level on the bench, that the fuel levels in the bowl would also be at the same level, but this is not always the case.

S.
 
The valves have spring loaded pins. Could these be weak and contributing to the problem?

The brass seats have an o-ring that may be weeping.
It seals the brass seat to body gap.
If it is seeping fuel it will not matter how new or good the needle valves are.
 
Hi,

Are you floats really floating? Or are they leaking, taking on fuel and not floating? Check the floats for damage, pin holes, cracks at the seams, etc.


Thank you for your indulgence,

BassCliff
 
kevsgs said:
Well the fuel level rises above the floats and runs out of what I believe is the air ports for the mixture, the holes at the bottom facing towards the airbox. When the needles should be stopping the fuel as the float hits its hieght, they're not and it just floods/flows out of those holes.
Click to expand...
(I'll start with I'm not an expert and I didn't sleep at a Holiday Inn last night.);)

If you have new OEM needle valve assemblies that would seem to rule out bad parts, maybe there is something causing too much pressure on the needle valve assembly, the floats are engaging the valve incorrectly, or the floats aren't floating like BassCliff mentioned.

I think I've read here that if your temp tank is too high, that can create too much pressure on the needle valve assembly. Maybe someone else can answer if a clogged air passage in one of the carbs can create the wrong force somewhere else.

I just started learning, testing and messing with float levels and needle valve assemblies on two differnet sets of VM carbs. I check the float levels with the clear tube method out of the drain hole. On mine, I've noticed just very slight variations in how the tang on the float engages the needle valve can make a noticeable difference in the fuel level. How you bend, or how level each of the red lines in picture-A can affect exactly how the tang hits the valve needle. Also, picture-B show the tang itself with the red line, if bent slightly, it can affect the needle valve too. A little bit of change has a bigger affect than I originally imagined.

floatset.jpg
 
Made some progress

Made some progress

So the new O-rings came in. Got them installed and while in there just went through the jets to make sure they were nice and clean. I have previously checked the floats, that was actually one of our first thoughts but they function perfectly as far as floating, no holes at all. So with new O-rings in I set up for bench test. First try at .81", factory spec, I turned on the fuel and the bowls filled then the fuel stopped flowing. Now with this setup it would be like running on PRI. After about 15 mins they began to overflow just a bit, and I mean not much at all, a couple drops every few mins. Just out of curiosity I set them to .90", float height, with this it took 45 mins before it began to overflow, and it was the same, just a few drops over time. So I chalked it up to possibly running on PRI, so I set float height back to factory spec and put the carbs on the bike. This is where it got interesting. On PRI the carbs would overflow, but on ON they would not, this is with engine off. So with engine running, PRI would still overflow, but the ON position worked great. They were not overflowing, the bike ran for a few minutes with no problems to the point we were starting to adjust the idle and thinking we had finally got her going. Then it just stopped, like it was out of gas. Which is what started happening. I could fill the bowls with the PRI, then turn it to ON, and it would run fine but was just sucking the fuel out of the bowls and then die, the bowls for some reason were not filling anymore while it was in ON position. But for a good few minutes it was perfect. So I am momentarily stumped. Any ideas or suggestions?
 
I am thinking it is possibly the petcock since the bowls are getting gas or running without overflowing depending on where the petcock is positioned. Today I'm going to put it all back together and hook up airbox and see if this helps as far as it getting to bowls full while on ON position, still have no idea what happened there as it was doing fine for a bit, then just quit filling the bowls unless you let it sit for a minute or turn to PRI. Would love any suggestions.
 
On vs prime

On vs prime

Since you said it just wont flow on ,,,,,ON,,,,,,,, but will flow on prime, I would be checking that vacuum line first thing, I think you already said you have a new one, be sure everything is attached correctly and its not bent off and closed due to the tuning efforts. The next thing, would be the source of vacuum, which is the number two carb, right,??? Did your tuning do something that would stopper off the source of vac to the petcock. The only thing I think that would do this, is a wide open throttle, but that is a very long shot if youve had the bike running. Is it possible for a diaphragm leak to affect the vacuum to that source????


Here is hoping youve got a kinked off vac line to make it easy for you.

Since no one has mentioned this, except for cliff alluding to it, if this overflow continues, you may want to pull the floats, if they are plastic, check for casting flash on the sides of them, take the flash off with a file. Also, Ive heard of oversized carb bowl gaskets interfering with float operation, it may be best to trim them back with a scissors if there is more than say, a steenth of an inch of overlap into the float bowl area. I do this routinely when having the carbs apart on a new to me bike, but have never actually experienced the problem itself.

Fuel flow when its not supposed to,, is very dangerous, if that bike is kept in an attached garage, woe be to anyone sleeping in the house if it starts leaking and a source of ignition is present. Ive also read of a guy going down the road on a gas leaking bike, and the thing caught fire while he was still riding it, he was fortunate he didnt end up with toasted gonads on that deal. I personally had an xs eleven that had a leak that I couldnt find, it turned out to be an opening that I had forgotten to close, it was very scary but there was no source of ignition so all was ok. I also had a car backfire, and literally lite the throttle body on fire, I can tell you there was some mad dashing looking for a way to put it out before I finally smothered it with an old tee shirt. To this day, there are melted looking plastics on the throttle body, but the car runs just fine with it like that.
 
Last edited:
banditom said:
Since you said it just wont flow on ,,,,,ON,,,,,,,, but will flow on prime, I would be checking that vacuum line first thing, I think you already said you have a new one, be sure everything is attached correctly and its not bent off and closed due to the tuning efforts. The next thing, would be the source of vacuum, which is the number two carb, right,??? Did your tuning do something that would stopper off the source of vac to the petcock. The only thing I think that would do this, is a wide open throttle, but that is a very long shot if youve had the bike running. Is it possible for a diaphragm leak to affect the vacuum to that source????


Here is hoping youve got a kinked off vac line to make it easy for you.

Since no one has mentioned this, except for cliff alluding to it, if this overflow continues, you may want to pull the floats, if they are plastic, check for casting flash on the sides of them, take the flash off with a file. Also, Ive heard of oversized carb bowl gaskets interfering with float operation, it may be best to trim them back with a scissors if there is more than say, a steenth of an inch of overlap into the float bowl area. I do this routinely when having the carbs apart on a new to me bike, but have never actually experienced the problem itself.

Fuel flow when its not supposed to,, is very dangerous, if that bike is kept in an attached garage, woe be to anyone sleeping in the house if it starts leaking and a source of ignition is present.
Click to expand...
I was just about to put the carbs back on, but I think I will open up the bowls again and take a look at those floats. They are not leaking and they float great, one of the first things we checked. However I have not checked for any casting flash or overlaping gasket, so I'll check that real quick before re-installing. The problem now does seem to be vacuum related so I will also make sure nothing is blocking the line or anything wierd there. I also plan on puting in an inline shutoff to know for sure the fuel is turned off when not in use. Don't think its necesary but like you said I don't want to take that chance as it is an attached garage. When the tank is off and currently half full of fuel there is absolutely no leaking though, but better to be safe. I'll go try these things and see what I come up with....thanks.
 
be sure to let us know what cures it

be sure to let us know what cures it

be sure to let us know what cures it
 
Well went through and checked the floats, nothing that they would be catching on. I've even got the back tang set so that the bowls cannot fully make contact when they are at their lowest level just in case they were getting caught there. Put it all back together in hopes of something working itself out, (because that always happens right? :lol:), but it is still doing the same thing. It fires up, runs and sounds smooth, especially with airbox connected again, but it dies as soon as it burns through whatever fuel was in the bowls. I have to turn it to PRI to fill the bowls again. So at this point I'm thinking its got a bad petcock. The vacuum is not allowing the fuel to flow through the petcock. I did look at the vacuum line, looks perfect, no obstructions, even with tank on there is nothing pinching or kinking the line. I'm wondering if I try taking it apart again if I can figure out something, the spring on the vacuum side of petcock for the diaphram felt nice and strong and worked properly when we tried it. The petcock is the last part of that system that is not new, I don't know, I guess I'll go pull it apart and see what I can see. Again any advice or suggestions are very welcome!
 
put a long clear hose, onto the vacuum line and suck....I know that don't sound right, but you know what I mean,,,,,,as in your acting as the vacuum, and see if you can get fuel to come into the feed hose.....

please use a long piece of hose, I don't want you to suck in fuel, that would not be a good thing
 
GateKeeper said:
put a long clear hose, onto the vacuum line and suck....I know that don't sound right, but you know what I mean,,,,,,as in your acting as the vacuum, and see if you can get fuel to come into the feed hose.....

please use a long piece of hose, I don't want you to suck in fuel, that would not be a good thing
Click to expand...
I just pulled off the tank and went to drain it to maybe take a look at the petcock, and I actually did just that. With a tube draining the gas into a can, i hooked the vacuum line up and sucked on it, (yes that does sound funny,lol, but whatever she needs to run,lol), no fuel would flow while in the ON or RES position until I sucked on the vacuum line. And of course on PRI it just free flowed as it should. A couple things seemed a bit wierd to me but I don't know a whole lot, I did have to suck pretty hard to get the fuel flowing. The second thing was as it got towards the last of the fuel a lot of air was going through the line with the gas. Should I have to suck that hard to activate the vacuum, and should there be a lot of air bubbles flowing with the gas towards the last of the tank?
 
I'm obviously not getting enough vacuum to make the petcock open up and allow fuel in, would that be a bad petcock or something else?
 
I am no expert on these things, the petcock, but perhaps the diaphragm is shot, or in backwards, or something to that effect ? I don't think it should take a whole lot of vacuum...?
 
GateKeeper said:
I am no expert on these things, the petcock, but perhaps the diaphragm is shot, or in backwards, or something to that effect ? I don't think it should take a whole lot of vacuum...?
Click to expand...
Well that is definately the problem, its not opening up the valve to let fuel in, so I'll go take it apart and see if I can fix it. It did seem to have to have a whole lot of suction to get it to work. While I'm messing with that I think I'll put the carbs back on the bench test and make sure they are still doing what they are supposed to as well. This is all very frustrating...something should have worked by now. I guess besides learning about carbs I'm also learning more patience. :eek:
 
You must log in or register to reply here.
Back
Top