fuel gushing from top of engine

[trantony]

upon starting 98 tourer a few days ago and rode around the block. I immediately smell strong gas odor. Engine started starving for fuel so I headed home, at which time I saw gas pouring from engine bay area. Anyone on hear have any idea as to what this may be? thanks for any and all responses.

[longrider]

Two things come to mind right off.  First,  if the m/c hasn't been used and started for a some time the o-rings in the carb bank will have dried a bit and leak from the rails.  Happens to me each spring with m/c carbs drained for winter storage.   They should swell and be fine after sitting overnight.  The other is a petcock diaphragm failure.  May require a rebuild kit.

[hubcapsc]

Look into the petcock first, it is easier... if the petcock is
that bad, you'd probably be able to reach up to it and feel
of it and it would be wet... my carb rails have never
leaked (that I know of) so I've never rooted around trying
to diagnose that...

-Mike "the only time you have too much gas is when you're on fire..."

[Bagger John - #3785]

Option #3 is the fuel line running from petcock to carbs has come loose or developed a leak.

[trantony]

Im thinking a fuel line may have come loose or maybe a split in plastic manifold to carbs. the bike was running out of gas when I got home, with a full tank. So I thinks petcock is working properly. This was a major gas leak, it dumped almost a 1/2 gal. of gas from time I pulled in driveway to time shut it off. I had gas streaming down driveway as I pulled in. Fuel gusher stopped immediately upon shutting down engine.
Going out to see if I can find something now. Will keep posted. Thanks guys.

[trantony]

Just pulled tank and air cleaner box and no obvious issues by looking. No split hoses or loose hose ends. Will try to put tank back on tomorrow temporarily and replicate gas leak using a vacuum gauge on petcock to open. Any and all ideas are welcome.

[Savage]

See if the gas is pouring out of one of the carburetor vent lines, which could indicate a stuck float.

[Mooskee]

The starving could be due to the petcock diaphragm failing. It could leak and not open the petcock. Like someone said earlier you should be able to see/ feel gas running out from the petcock if that is the problem.

If it is the fuel rails you will be able to see wet gas between the carbs on the gas line T or the aluminum gas rails.

If you have a stuck float bowl float the gas will be running out one of the rubber tubes that run to the front cross plate on the carb bank.

[hubcapsc]

with your tank off, you could do the simple
petcock vacuum test...

http://www.valkyrieriders.com/shoptalk/petcock.htm

-Mike

[Jims99]

Sounds to me like the petcock is working fine. Could be split in line, fuel rail o-rings or sticking float. The o-rings usually fix themselves if not split. It may not be starving for fuel but flooding. Be careful if you put  tank on and run gas through, if it’s a float, it could hydrolock. Hopefully something simple.

[The emperor has no clothes]

Im thinking a fuel line may have come loose or maybe a split in plastic manifold to carbs. the bike was running out of gas when I got home, with a full tank. So I thinks petcock is working properly. This was a major gas leak, it dumped almost a 1/2 gal. of gas from time I pulled in driveway to time shut it off. I had gas streaming down driveway as I pulled in. Fuel gusher stopped immediately upon shutting down engine.
Going out to see if I can find something now. Will keep posted. Thanks guys.

My initial thoughts were the fuel rail orings. But I never had near that much leaking out.

[trantony]

Ok guys, just fed fuel down fuel line with syringe and started bike to check for leaks. No signs of a leak anywhere, but not sure if it would show up without tank installed. It was very hard to start, sounded like it was flooded. Finally got it started and it seemed to run ok. I checked fuel lines for splits, went ahead and changed them out while I had it all apart. What are the lines from tees between carbs 1&3 and 2&4 for?  I have these lines open to atmos. because I did the emissions delete years ago.

[sdv003]

This sounds like fuel rail o rings.  when i first bought my tourer, it had sat for a while.  Had the gas that was pouring out onto the engine ignited, I would have been turned into a roman candle.  You can get quite a bit of gas thru dried out o rings.

[98valk]

the o-rings are made of Buna-N aka Nitrile. they don't dry out unless left in the sun.

the end nuts of the connecting rod that holds the carbs together can vibrate loose over time allowing leaks.   simply tighten both end nuts.

at about 20k miles the left bank of carbs on my bike started leaking. nuts were loose, tightened them, added a dab of silicone to the exposed threads and hasn't leaked for over 45k miles now.

[Ricky-D]

Ok guys, just fed fuel down fuel line with syringe and started bike to check for leaks. No signs of a leak anywhere, but not sure if it would show up without tank installed. It was very hard to start, sounded like it was flooded. Finally got it started and it seemed to run ok. I checked fuel lines for splits, went ahead and changed them out while I had it all apart. What are the lines from tees between carbs 1&3 and 2&4 for?  I have these lines open to atmos. because I did the emissions delete years ago.

I think you're pretty lucky.

In my opinion I think you had a stuck float valve assembly in one of your carburetors and the gasoline was pouring out of the float bowl overflow.

That would account for the poor running that you attributed to a lean running condition.

The real danger was that a hydrolock situation was extremely available when the engine was cut off.

That's where I think you ducked the bullet.

***

[Mooskee]

What are the lines from tees between carbs 1&3 and 2&4 for?  I have these lines open to atmos. because I did the emissions delete years ago.

Those are supposed to be open to atmosphere. They are the overflow lines if you have a stuck float in a carb bowl.

[trantony]

12/3 Update:
Today I checked fuel petcock, turned valve on and had no gas flowing or leaking from tank. Then I put vacuum pump on petcock and fuel immediately started flowing. I think this pretty much eliminates the petcock as a problem. Then I remove all spark plugs and checked for flooded plugs, also turned engine a few times to check for gas in cylinders. Showed no signs of flooded cylinders, but not sure this will prove anything as bike has been sitting for a week since this all started. Wouldn't fuel drain pass rings into oil sump during that time? Tomorrow I plan to put tank on bike temporarily without air box and run engine to see if I can find leak. Any suggestions?

[recman25]

I've got the same "problem"! The gas will leak out of the fuel rails after it sits for a while. I let the engine run for as long as Im comfortable, then shut it down and sit, the start it again. Eventually it fixes itself. This drives me insane, but apparently its a common occurrence. I'm  curious if anyone has any thoughts about the 10% ethanol in gas these days. I know in boats it has a habit of rotting the rubber fuel lines.

[trantony]

Recman25 I only use ethanol free fuel, and have for years now. Only use ethanol fuel when on trips and can't find ethanol free.
Update 12/5:
Today put new plugs in and I installed tank temporarily and tried to start bike with no luck. I did not install airbox though. Seems like it was flooding and would not start. I know it should run without airbox because I had it running a couple of days ago on temporary gas supply. Tried with full choke and no choke, but it would not start. Ran hot battery down to nothing trying. Got battery on charger overnight. Guess my best bet is to remove carbs and do a rebuild. Still don't know if fuel was coming from carb overflow or fuel rail o rings. Anybody....?

[trantony]

Anybody on here know where to get best carb kit? I see All Balls has one, but not for 1997. They say it is for 1998-2000. It also says "not for street use", whatever that means.

[Mooskee]

Redeye has great kits. I use them because of quality parts and he includes great tools for testing everything. Get his carb rebuild kit and also purchase bowl gaskets. https://redeye.ecrater.com/

I also replace the main and slow jets and the bowl float needles. Jets R Us has the original Keihin jets so you know what you are getting. www.jetsrus.com

[rug_burn]

  I think I'd investigate whether one or more your floats are stuck...
Even if the petcock was just passin gas thru it, the carb floats and needles should stop the flow, for the most part.
    And o-rings will eventually harden and not work too well, but they just tend to seep gas.

  I was wondering if there is one of those passages on top of the carbs where you could unstick the float by pushing it down with a dulled piece of wire or small dowel through the hole and pushing on the float.
    Has anybody ever found that to be possible?

[Valker]

I’ve unstuck floats a couple of times by whacking a crash bar with a rubber mallet. Never had to touch the carbs in 190,000 miles other than that.

[9Ball]

Anybody on here know where to get best carb kit? I see All Balls has one, but not for 1997. They say it is for 1998-2000. It also says "not for street use", whatever that means.

The all balls kit has junk components compared to Redeyetech kit.  I ordered the all balls kit to check it out and returned it for a refund.  I rebuilt the carbs on my bike two years ago and last year I refurbished my spare set of carbs will all new internal components.  The instructions and tools that come with Rich’s kit are the best available.

[trantony]

Thanks guys! I had already ordered an All Balls carb kit and a Redeye Fuel Rail kit to eliminate any and all issues. Did find my petcock valve would not hold a vacuum. As long as I kept pumping vacuum pump, gas would flow. As soon as I stopped pumping vacuum pump, fuel flow would stop. Rebuilt, petcock cover set. Currently have carbs sitting on bench awaiting rebuilt kits. I figure with 94K miles on her, a rebuild couldn't hurt. Will updated findings later.

[gordonv]

The petcock only works while there is a vacuum. So it sounds like it working.

Or do you mean when you apply a vacuum it works, but the vacuum slowly leaks down and the flow stops? (perforated diaphragm)

FYI
There is a way to revers your petcock workings, so it stays open (flows). Just the kind of thing you want to know when on a road trip and have this problem.

[trantony]

Update 12/19:
Got All Balls carb kit and finished rebuilding all 6 carbs. Didn't find anything that was an obvious problem though. Changed all orings in fuel rail and vacuum rail. In process of reinstalling carbs on bike now, having issues with air box connections to carbs. Just doesnt want to connect. Any recommendations?

[gordonv]

There is many ways to get the ports into the tubes.

Some use zap straps to pull them together on the air box. Then cut them off as they make contact. Look it up.

A 2x4 on top of the air box and a cargo strap to apply the downward pressure.

I was able to just press it down slowly, let them feed in with easy pressure.

Alcohol makes the rubber slippery.

Are you sure the ports are getting into the tubes? A mirror to get behind them, and a pick to align the rubber.

[hubcapsc]

Alcohol makes the rubber slippery. 

And wd-40 too... it won't matter if some goes down in there, wd-40
is a great starter fluid... make the tubes slippery and carefully work
them down everywhere. Make double sure they're all seated  before
you call it good... 

-Mike

[trantony]

Thanks gordonv and hubcapsc. Will try the compression straps and 2x4, and I am using Marvel Mystery oil for assembly on all rubber parts. seems to work well. Thanks guys. Will update.

[Led]

YUP!!!    I am on the fuel line O-ring bandwagon.   I have had to allow mine to sit for a couple of years,  and it is if the fuel line is not even hooked up anymore when starting it up again!   Fuel runs all over.

I go back a few hours later?   All "fixed"??    

[trantony]

Update 12/22:
Got rebuilt carbs back on bike yesterday afternoon. Really struggled with the airbox to manifold connections But persistence once again paid off. Mounted tank this morning, added fuel, put vacuum on petcock to pre-charge carb bowls, turn engine over and over, and over.... you get it. Then suddenly realized I only had enough fuel to use the reserve switch. Flipped it to reserve and fired right up. Tickled to death, only had to adjust idle up a few hundred rpm and took her out for run. Seems to be running great. Only issue is engine holds at about 1200 rpm for about 3-5 secs. before retuning to 900 rpm where I set it. Doesn't seem to have any other issues at all. Could the idle issue be a pilot screw adjustment?
Would like to say thanks a lot for all who sent me ideas and recommendations, especially Dray smith from Arkansas for his excellent youtube video series on Valk carb rebuilds. This is a must watch video series for anyone doing a carb rebuild. Couldn't have done it without you guys.

[Jess from VA]

Update 12/22:
Got rebuilt carbs back on bike yesterday afternoon. Really struggled with the airbox to manifold connections But persistence once again paid off. Mounted tank this morning, added fuel, put vacuum on petcock to pre-charge carb bowls, turn engine over and over, and over.... you get it. Then suddenly realized I only had enough fuel to use the reserve switch. Flipped it to reserve and fired right up. Tickled to death, only had to adjust idle up a few hundred rpm and took her out for run. Seems to be running great. Only issue is engine holds at about 1200 rpm for about 3-5 secs. before returning to 900 rpm where I set it. Doesn't seem to have any other issues at all. Could the idle issue be a pilot screw adjustment?
Would like to say thanks a lot for all who sent me ideas and recommendations, especially Dray smith from Arkansas for his excellent youtube video series on Valk carb rebuilds. This is a must watch video series for anyone doing a carb rebuild. Couldn't have done it without you guys.

How about a throttle cable adjustment?  Is the throttle sleeve moving freely on the handlebar?

[Ricky-D]

Could the idle issue be a pilot screw adjustment?

Yes.

[gordonv]

Only issue is engine holds at about 1200 rpm for about 3-5 secs. before retuning to 900 rpm where I set it.

I haven't heard this for almost a decade now. If I'm remembering right, this seemed to happen about 10 years ago, which is when I got my 1st Valk IS, and had the rpm take a sec or 2 to settle back down to idle, after I came to a stop.

Wrote the bike off, so never did figure it out. But I think the issue is un-diagnosed, and not something to worry about. (44k miles, sitting in the dealership, and put 5K miles on it in 6 months. It only happens when stopped, so don't stop, ride it 

[trantony]

Thanks guys, I'll check all pilot jet screw adjustments when things warm up a bit. I replaced them and currently have them set as they were before rebuild. All but 1 was set 2 1/4 turns, the last was set at 2 1/8 turns but, didn't think that would make a difference. Also bench synchronized carbs after rebuild according to D-ray smith youtube instructions. Will update.

[Ricky-D]

Thanks guys, I'll check all pilot jet screw adjustments when things warm up a bit. I replaced them and currently have them set as they were before rebuild. All but 1 was set 2 1/4 turns, the last was set at 2 1/8 turns but, didn't think that would make a difference. Also bench synchronized carbs after rebuild according to D-ray smith youtube instructions. Will update.

An additional treatment I would suggest to perform would be to get a spray can of lubricant and generously spray the complete linkage on all the carburetors generously while working the throttle.

First off, it's important to certify any carburetor problem is not related to a restricted movement issue.

[trantony]

Absolutely Rickyd! I had that issue when I first installed carbs, and determined I had the throttle cables adjusted too tight. Was hanging up at half throttle, readjusted looser and working like new again. Thanks for heads up.

[Madmike]

Update 12/19:
Got All Balls carb kit and finished rebuilding all 6 carbs. Didn't find anything that was an obvious problem though. Changed all orings in fuel rail and vacuum rail. In process of reinstalling carbs on bike now, having issues with air box connections to carbs. Just doesnt want to connect. Any recommendations?

I have a couple of different "cotter pin pullers" that I use on hoses to help put them on.  One is a Craftsmen that is about a 1" hook and the other is a Mac that is longer.  I have had them both for 35+ years.

[trantony]

Final update 12/29/20:
OK guys, think I about got her wrapped up. Idle issue seemed to have solved itself, ok by me
Took her out for about a 60 mile run yesterday and she seems to be running great, no hesitations, backfires or the like. Think Ill be able to close this issue on carbs after I once again thank all who helped with all the feedback on my project. Thanks again guys!!