Another "No Run" possible Petcock issue-Solved

[Fazer]

My son got stranded last night when his 2000 tourer quit on him.  Cranking fine but even with choke on it would barely run and soon as throttle was touched it would die.  Tried opening the gas cap and starting with petcock selector on reserve, but no joy.  We have not had the tank off and he has ridden it at least 60 miles since we got it back on the road a couple of weeks ago.  I am suspecting either a bad vacuum line or a petcock in need of a new cover set. No history on the bike with respect to petcock, so even if it turns out to be something else, will do a new cover set.  We will also check air filter as long as the tank is off.

Thoughts or suggestions are welcome.

Greg

[9Ball]

Maybe some bad fuel?  Did he stop to fill it up and then not get it restarted?

[The emperor has no clothes]

Vacuum line and cover set would be my prime suspects. 

[Foozle]

Greg:  Don't overlook the basics.  I did - and it cost me a lot of time "fixing" things that weren't broken.

If the petcock turns out to be functional - and the tank is venting properly - make sure there is sufficient "straight line" decline in the fuel line from the tank to the "T" out to the carb banks.  If there is even a slight bend, plateau, rise, etc. - there may not be enough head pressure from an emptying tank to get fuel to the carbs.  Lengthening the fuel line for ease of connection to the petcock can result in this situation.  IMHO, if reattaching the gas line to the petcock isn't a PITA, your line may be too long.

Trying to start the bike with a full tank of gas should test this theory.

Terry

[Willow]

It appears to me we may be jumping to a conclusion.

The petcock allows fuel to flow filling the carb bowls.  The engine runs off fuel from the carb bowls.  If the petcock is failing it would mean no more fuel is getting to the carb bowls.  The engine would die after the fuel bowls have been emptied or if they were already emptied would not start at all.

What you are describing sounds more like a fuel mixture issue.  Way too rich?  Way to lean?

[Fazer]

Thanks everyone.  It will restart but only with the choke on, and will not stay running.  It has run perfectly up to this instance. It sat for about 9 months with full fuel and Techron added for storage amd has been ridden for about 50 miles over the last few days.  We will remove the tank and check the operation of the petcock. 

[gordonv]

What you are describing sounds more like a fuel mixture issue.  Way too rich?  Way to lean?

It will restart but only with the choke on, and will not stay running.

It could still be a delivery issue.

make sure there is sufficient "straight line" decline in the fuel line from the tank to the "T" out to the carb banks.  If there is even a slight bend, plateau, rise, etc. - there may not be enough head pressure from an emptying tank to get fuel to the carbs

Fuel filter? Non OEM fuel line/setup?

It does sound like a fuel delivery issue, just enough to sputter when the enricher is on, but not enough for anything else.

[The emperor has no clothes]

I think sometimes when the peacock goes bad, it’s not all at once. Might be delivering just enough fuel to start it with the enrichener on.

[Willow]

I think sometimes when the peacock goes bad, it’s not all at once. Might be delivering just enough fuel to start it with the enrichener on.

Not to extend the discussion too far but sometimes folks are overly anxious to blame a petcock.  It could be a fuel delivery or fuel mixture issue but as described simply cannot be a petcock issue. 

The petcock delivers fuel to the carb bowls.  Petcock issues do not immediately show up such as when the throttle is initially increased.  Those issues show up over time as the bowls run low on fuel.  Filled bowls will run the Valkyrie for about two miles.  Empty bowls will not start a Valkyrie. 

[indybobm]

You can open the carb drains to see how much fuel is in the carbs.

[Ricky-D]

I agree with Willow.

The bike sat for a long time without running.

Sure, there was Techron in the tank, but that is no guarantee it will have prevented the problem now being encountered.

Just pouring some additive in the tank is not enough. There is a required procedure that must be followed.

Who's to say it was perfect before being stored?

The carburetors need proper cleaning.

***

[F6BANGER]

As others have said, drain the carbs from the carb drain screw. I would also drain the tank and add fresh gas to it. Put some additive (techron) that will help clean what may have gotten in the carbs. May work, may not. If not Ricky-D is probably correct, you may be looking at a carb rebuild. Try the easy thing first.

[Jim in Idaho]

Techron not necessarily your friend for storage.  I would suspect water separation.  Drain tank and fresh fuel if it were me

[Fazer]

Thanks for the help. 

Here is what we will do--
--remove tank and check status of vacuum line. 
--If vacuum line is OK, we will test operation of petcock.  If either of these fail, that would prevent fuel from entering the carbs. 
--If vacuum line and petcock are both good, then we will drain the float bowls. 
--If we get gas out of the float bowls it, we will drain tank and fill with new fuel and strong dose of Techron.
--Last resort is a carb clean/rebuild.

Not sure when we can do this, but will post our results.

[Gryphon Rider]

I certainly wouldn't use Techron or any other fuel system cleaner as a fuel stabilizer for storage, as that's not its purpose, and the extended exposure to the detergents might be harsh on various components.  Soap and water are excellent for washing hands, but I wouldn't soak my hands in soapy water for days at a time either.

[Pluggy]

If the bike has been sitting, cleaners like Techron loosen dirt and varnish inside the fuel tank.  That material, as particles or gummy stuff, can clog the fuel filter or perhaps the carbs.  I have read of guys dumping a whole can of Seafoam into a CB900C.  The bike fails to run because the contamination is loosened, suspended, and flows with the fuel.  Guys think they are doing their bike a favor dumping a whole bottle of that stuff in.  

Try taking the tank off, discarding the gas, cleaning the filter, and starting over with fresh gas.

[John Schmidt]

Before you jump in and remove the tank do the easy stuff first, drain the carbs to see if there's anything in there. If so, then it doesn't appear to be an immediate delivery issue. If they're dry, then open the petcock and use a MityVac to engage the diaphragm by pulling the vacuum tube off #6 (or wherever yours is located) and apply some vacuum. Once you have done so, bend the vac. tube back on itself and clamp with a closepin or similar. That will open the petcock without the motor running and keep it open while you check to see if the carbs are now filling by opening their drains again. If that all works, you apparently need a good cleaning....partly due to using Techron for something it wasn't designed for....see Pluggy's post.

In the future if you want to store the bike, use something line marine Stabil, run the bike for a time so you know it's in the system. Shut it off and leave it alone until you're ready to really ride it, don't run it for short periods in storage thinking you're doing it a favor.

One thing you might try at the beginning is rather simple if done before draining the bowls. Attach a MityVac to the carb drain line under the bike, then pump up some good vacuum on it. Next open one bowl drain screw and see if you get a bunch of debris pulled out by the vacuum. Doing this procedure creates some liquid turmoil within the bowl and often causes debris to be sucked out. Close that drain screw and go to the next carb and repeat, do one at a time....you might find one or more has no fuel in it, and that would part of your problem.

[Fazer]

It's fixed. 

Justin trailered it back to my shop where we have large bay used to letter vehicles and parked it there.  I had to move it this morning to get it out of the way, and noticed that it had very little gas--in fact it was empty.  Duh.  This was a bike he bought from a local guy that I filled up with gas on my way back to the shop and re-zeroed the odometer, as I always do.  It read 56 miles this morning.  I am positive I filled it, although it was last spring.  He rode it around the property here but it was never out on the road.  Anyway, in the immortal words of Carl in Slingblade, "put some gas in there, uh huh."  Just glad we thought to do this before removing tank etc. 

Sorry to excercise all the Forum brains for nothing.  Embarrassed. 

[indybobm]

Have you checked the oil level to see if it is higher than it is supposed to be. Might smell like gas.

[Fazer]

How would gas get into the oil?  That sounds bad.

[The emperor has no clothes]

How would gas get into the oil?  That sounds bad.

If a float is not seating and letting gas into the cylinder, it could be getting by the rings into the crankcase. It would be a good idea to check it like indybobm suggested.
 I'm not sure I understand the fix. It was out of gas ? Did you guys try it on reserve earlier ?

[Fazer]

Meathead--he apparently tried to resrtart several times without going to reserve and thus drained the float bowls.  Then tried reserve but did not let the bowls refill.  It's a new bike to him and he is not familiar with the feel of the need to go to reserve.  I am still wondering what happened to all the gas I thought was in it for the last 8-9 months.  Checked the oil and it is fine.  No gas smell, and if that much drained into the cankcase, it would have been oozing out the dip stick tube.  besides, we just changed the oil and no surprises.  Only thing I can think of, is he road it more than he thought.  we had the front wheel off for new tires and must have bumped the odometer some how.

BTW, I had stated earlier that we had introduced Techron to the fuel.  It was Berryman's B12, not Techron.  Don't know if that is any different.

He is going to refill the tank and see what happens.