gas in bottom end

[rdmcguy]

A little help if you will please,
My petcocks/needles leaked to the point of filling my bottom end with gas,
I am unable to find the thread describing the procedure to flush and make sure I don't create /allow any future problems..I have drained it and will replace the filter...What else??
Thanks in advance

[skids]

A little help if you will please,
My petcocks/needles leaked to the point of filling my bottom end with gas,
I am unable to find the thread describing the procedure to flush and make sure I don't create /allow any future problems..I have drained it and will replace the filter...What else??
Thanks in advance

There are several things that could have happened. I'll tell you a way that you can flush-out the needle seats if otherwise loose debris is preventing sealing when the bike is off. 1st, make it safe by removing excess gasoline in the filter area and put the airbox back together.

1. Stop the flow of gasoline to the carbs. On a special, I think all you have to do is switch the petcocks to "off" and on a standard, you need to remove the vacuum hoses at the petcocks (and plug off the tubes to the engine with golf tees).
2. Start the engine on the "prime" position. This causes fuel to be fed from the bottoms of the bowls (if those bowl jets are not plugged).
3. Run the engine until it starts sputtering, then switch the petcocks to "Prime." Run the engine above 3000 rpms so that any particle is passed through the main jet instead of the tiny pilot jet.

The theory is that you will open the needle seats as much as you can and flush out the seat area with gas. This has worked for me.

Other issues that cause leakage can be corrosion on the float pivot pin, stuck valve needle pin, bad o ring on later model float fuel valve, sinking float, leaking octopus unit or petcock unit. I am sure there are more, but I can't think of them right now...

[donebysunday]

A little help if you will please,
My petcocks/needles leaked to the point of filling my bottom end with gas,
I am unable to find the thread describing the procedure to flush and make sure I don't create /allow any future problems..I have drained it and will replace the filter...What else??
Thanks in advance

First find why and fix the reason for the overflow !
Is this the 78 or one of the specials ?
If one of the specials do you turn your fuel taps to the off position when
parked for a long time ?
From what I've read you have a leaking wizzer valve (washer in the petcock with 5 holes in it) and or other leakage, (vacuum shut off on 78 petcocks) on the specials the octi vacuum shutoff, oh and float needles should stop fuel from overflowing.
Do you park on the center stand ?
You should if parking for any length of time. The side stand sends all the fuel to #1 carb and puts all the carbs at an angle causing possible sticking floats.

(1) Take the fuel lines off the petcocks and see if they are leaking, on the specials switch to OFF to check leakage, the 78 has the vacuum shutoff in the petcocks switch them to ON/RESERVE so if they leak it's the vacuum shutoff and or the washer with 5 holes in it, special or standard if leaking first thing is that washer, 2 different part #s between special and standard. May be possible to clean up the sealing surface for the O-ring that seals the vacuum shutoff ?
(2) On the specials check the octi by switching the petcocks to ON or RESERVE, should be no fuel going to the carbs, if there is the vacuum shut off in the octi needs replacing.
(3) Switch to prime with bike on center stand sitting level, do the carbs start to leak anywhere after a few minutes, float bowl gaskets, inlet, outlet, overflow vents ? This would mean the float needles/seats are leaking, may be able to clean them up ?

[rdmcguy]

Thanks so far..

Thanks so far ,It is a special with a standard tank
,cannot put on center stand (Kerker header)I plan to check/rebuild petcocks
and needles and seats....I had not ridden it for a while,and noticed it leaking from the pulser coil area,,I did NOT run it..I just want to be sure to flush it completely before start up ..SO should I change oil and filter,run it for a few minutes and then drain and refill again?

[jetmechmarty]

2. Start the engine on the "prime" position. This causes fuel to be fed from the bottoms of the bowls (if those bowl jets are not plugged).
3. Run the engine until it starts sputtering, then switch the petcocks to "Prime." Run the engine above 3000 rpms so that any particle is passed through the main jet instead of the tiny pilot jet.

Huh....?

You have one or both petcocks leaking. You need to fix them properly.
Rebuilding Yamaha Vacuum Operated Fuel Valves (Petcocks.)

In addition, one or more of your carburetors has a leaking float valve. That needs to be addressed as well.

[donebysunday]

Thanks so far ,It is a special with a standard tank
,cannot put on center stand (Kerker header)I plan to check/rebuild petcocks
and needles and seats....I had not ridden it for a while,and noticed it leaking from the pulser coil area,,I did NOT run it..I just want to be sure to flush it completely before start up ..SO should I change oil and filter,run it for a few minutes and then drain and refill again?

OK, the standard tank can only use the standard petcocks. They have built into them the vacuum shut off, if I member right the standard's petcocks don't have OFF, just PRI/ON/RES, is that what you have ?
Can you post a pic ?
Don't put any oil in until this is solved.
You have options, I won't mention until we determine the problem !

[rdmcguy]

Me again

My photobucket skills are the worst...I am not concerned at this point about the cause, I think I have that covered...The fuel lines are completely disconnected from the carbs,My main concern is Any gas residue trapped in lower end....How many times should I flush ? or might it be a good idea to LIGHTLY blow a bit of compressed air thru the filler hole with the filter off and the drain plug open?

[motoman]

My photobucket skills are the worst...I am not concerned at this point about the cause, I think I have that covered...The fuel lines are completely disconnected from the carbs,My main concern is Any gas residue trapped in lower end....How many times should I flush ? or might it be a good idea to LIGHTLY blow a bit of compressed air thru the filler hole with the filter off and the drain plug open?

In answer to your queation...........wouldn't worry bout it too much. Drain it and change filter. Can let it air out a bit before filling with new oil or blow air in there to help evaporate fuel residue. New filter and 4qts of oil, motor will be fine.

[Schming]

My photobucket skills are the worst...I am not concerned at this point about the cause, I think I have that covered...The fuel lines are completely disconnected from the carbs,My main concern is Any gas residue trapped in lower end....How many times should I flush ? or might it be a good idea to LIGHTLY blow a bit of compressed air thru the filler hole with the filter off and the drain plug open?

IMHO, I would get the bike level/plumb so the crankcase drains properly.

Your idea of compressed air shouldn't hurt anything.

Using inexpensive oil & oil filter, refill the crankcase with the proper amount and run the bike, a few minutes til warm, on the support system you devise, shut off then drain again.

That should get you safe enough to refill with good oil & filter after the flooding problem is remedied.

[skids]

Huh....?

You have one or both petcocks leaking. You need to fix them properly.
Rebuilding Yamaha Vacuum Operated Fuel Valves (Petcocks.)

In addition, one or more of your carburetors has a leaking float valve. That needs to be addressed as well.

That is right, both have to be faulty for a leak, but if you can make one or the other function, it will get you by instead of getting a puddle of gas on the floor.

[CaptonZap]

With apologies to The Old Philosopher, (http://www.madmusic.com/song_details.aspx?SongID=270),

You say you parked your XS11 for a few years, and when you took it out of the collapsed shed and the cobwebs, and you cleaned it up, and changed the oil, and used the $8 a quart oil from the motorcycle dealer, because you wanted to make it up to your bike, and you put some premium gas in the tank, and found out the battery was dead, and when you came back and got the new battery in, you noticed a puddle of gas under the air box, and the oil level window was full of fluid, and pounding on the carbs with a screwdriver handle didn't stop the steady drip out of the air box, and now you don't have any money to get more oil, 'cause you had to buy a battery,
Is that what trouble'n you Bucko?
Well hold your head up high, take walk in the sun, show the world where to get off, and never give up, never give up, never give up that ship p p.

Let me remind you, do not try this at home. We are what you call professionals.

Take a metal pan big enough to hold the diluted oil, or portions thereof, in case you can't find a big enough container to hold it all. A clean 5 gal metal can works great.
Get an electric hot plate, an extension cord that will handle the watt draw of the hot plate, and that will reach a spot that is out in the open air, with no over hanging combustibles or ground cover, a router speed control, (on sale at Habba Fleight , Item #43060, for only $19.99, hurry, sale ends soon), a measuring stick that is oil and heat proof, and a kitchen thermometer that reads to 350f or so. If you meet resistance from your kitchen help about the thermometer, explain that you will return it in better condition, or at least as good of condition, as when you took it.
Besides, if you have to ask permission to use it, you aren't man enough to be doing this , so you better go back to watching Sponge Bob re-runs.
Place the can on the ELECTRIC, (and I can't stress that electric part strongly enough, DO NOT use the propane BBQ), hot plate and plug it into the speed controller, and that into the extension cord. ( The cord into an outlet, for our slow readers)
Suspend the thermometer so that the sensing tip is about an inch deep in the oil, and position so that you can read it. The ruler also.
Turn on the hot plate full blast, and monitor the temperature. As soon as small bubbles start rising, and you can see convection currents in the oil, turn the control down a skosh, and watch the temperature. You are trying to get to 250 deg F, and to set the controller so that it will hold that temperature.
Once that is achieved, you can find a cover that will not impede the fumes from escaping over the lip of the can, but will stop the malevolent magpies from any success in their bombing mission. Some professionals use three beer cans, crushed in the middle, placed evenly spaced on the edge of the can, and a metal garbage can lid placed on them.
I realize that you, being strapped for cash after buying a battery, won't be able to afford the beer, so you might invite Greg over, and maybe he will share, but if not, you can use his empties. JAT
Remember, gasoline fumes are heavier than air, so they will over flow the can, and run down to the ground and spread out, mixing with air, forming a combustible mixture until they are diluted enough to reach the lower limit of flammability. ( Look it up) Now you understand the open flame prohibition during this exercise.
For those who, if you will pardon the expression, like to kill two birds with one stone, the operation might be located so that the fumes ran down a prairie dog hole, and thus you might get double benefit from the vaporized gasoline.
Once the temperature reaches 250 and stabilizes, make a note of the fluid level, and go clean up the mess that happened as you were getting the oil drained. Don't try and kid me! Everybody makes a mess draining oil on an XS.
Check back every hour or so, and make a note of how much the fluid level drops. As the day wears on, the level will drop, and finally you will see it stop dropping. Give it another hour, and turn off the heat. Let it cool, and if the wind was blowing, strain it through an old tee shirt to get the big chunks out.
There you have it, for a few cents worth of electricity, and a days worth of fun on a par with watching paint dry, you have your oil back, almost as good as new.



The forgoing is intended as education material only, and the authors cannot be held responsible for any mishaps or degradation of product, should any readers try the process/s described. Your state may prohibit such disclaimers and actions, so you may or may not have certain legal rights, consult an attorney.