Gas/Oil Flooding Thing??

[Howell4706]

i am new at this so i'll try to explain the best i can.

so my petcock seemed to not shut off correctly for a couple of days. then one morning i come out and gas is dripping out of the breather pan. and the tank is empty.

i take the petcock off clean it up and put it back on. then try to crank it. it fires then dies and when it dies lots of gas pours out of (i think) the carbs. i take the air filter housing off so i can see better.

i tried again a couple of times with the same effect. i tried again this morning same. and everytime the gas has a gas/engine oil mix look to it.

any ideas, did my tank of gas empty out into the engine block?

[Danny Crawdad]

Yes, it did, your crankcase is full of oil and you need to change it before making any more attempts to get it started. Sounds like you need some rebuild kits for the petcocks. No big deal, but don't spin a bearing trying to rush it!

[jetmechmarty]

did my tank of gas empty out into the engine block?

It sounds like it. Don't run it that way.

What bike do you have? I just went through all of this with my Special. If yours is a standard, you need to rebuild the petcocks. If it is a Special, you need to rebuild the petcocks and the shutoff valve.

Your float vales in the carburetors are leaking. Try cleaning the carbs giving special attention to the needles & seats or replace them. (needles & seats)

[Howell4706]

i have a 1980 xs1100

so i need to drain all the oil. and rebuild the petcocks. i orderd one new(er) petcock, but i'll need either another petock or a rebuild kit. any ideas on a source for rebuild kits.

and are thr carbs easy to get off

[Howell4706]

and did i overfill the crank case oil, or is it just a petcock/carb problem

[Danny Crawdad]

Re: overfilling the crankcase, there's no way to tell now because you probably have an extra gallon of gas in there . But yes, you're overfull because of all the fuel in there. It thins the oil, and reduces its ability to lubricate, which is why it can be so dangerous to your engine to run without replacing the oil.

[Howell4706]

k

should i refill with good oil, run a few minutes then drain and refill again.

[jetmechmarty]

k

should i refill with good oil, run a few minutes then drain and refill again.

No. Just drain it and service it properly.

[GLoweVA]

Don't forget the oil filter. That filter cup can hold about a qt of fluid so don't just drain and refill, pull the filter out too and drain all that oil out also.
The filters are pretty cheap (about $5) so might as well replace that too.

[jetmechmarty]

i have a 1980 xs1100

so i need to drain all the oil. and rebuild the petcocks. i orderd one new(er) petcock, but i'll need either another petock or a rebuild kit. any ideas on a source for rebuild kits.

and are thr carbs easy to get off

Is your bike a standard or a Special (G or SG)? What do you mean by newer petcock?

For kits: http://www.georgefixs.com/servlet/StoreFront

http://youtu.be/DwfALaur7Zw

[Howell4706]

Is your bike a standard or a Special (G or SG)? What do you mean by newer petcock?

For kits: http://www.georgefixs.com/servlet/StoreFront

http://youtu.be/DwfALaur7Zw

i think mine is just a g , i'll have to check.

i got another petcock off of ebay

[DGXSER]

First look at the oil level with it on the centerstand, see if the level is high. That will tell you if the gas form the carbs ran into the crankcase.

The way the fuel system works is that the carbs have a float/valve assy. As the carb bowls fill with gas it lifts the floats and SHOULD shut off the fuel flow into he carb bowls. IF the float valves get a little debris in them, they will not shut off tightly and fuel will continue to flow into the carb bowls, filling the carb up to the throat, and fuel will run either into the air box or into the cylinders or both. It will run until it drains the tank.

On the tank are the petcocks they simply shutoff fuel supply to the carbs. The vacuum operated petcocks on the Standard or the vacuum valve on the specials shutoff fuel flow when the engine is not producing vacuum (not running). So if the carb float valves are working properly, the petcocks do not need to function to stop this issue from happening.

The fuel that runs into the cylinders will work its way past the rings and into the crankcase. this dilutes the oil and petroleum makes a horrible lubricant for bearings, so running your engine with the fuel in the oil is almost as bad as running with no oil in the cranksace.

The reason you got oily fuel into the airbox is that is where the crankcase breather line dumps to. With all the gas that seems to have made it into your crankcase, the oil level is so high your pushing oil out the vent (well, oil and gas mixture).

So, first issue is the carb float valves. then worry about petcocks and vacuum valve (OCTY).

[motoman]

First look at the oil level with it on the centerstand, see if the level is high. That will tell you if the gas form the carbs ran into the crankcase.

The way the fuel system works is that the carbs have a float/valve assy. As the carb bowls fill with gas it lifts the floats and SHOULD shut off the fuel flow into he carb bowls. IF the float valves get a little debris in them, they will not shut off tightly and fuel will continue to flow into the carb bowls, filling the carb up to the throat, and fuel will run either into the air box or into the cylinders or both. It will run until it drains the tank.

On the tank are the petcocks they simply shutoff fuel supply to the carbs. The vacuum operated petcocks on the Standard or the vacuum valve on the specials shutoff fuel flow when the engine is not producing vacuum (not running). So if the carb float valves are working properly, the petcocks do not need to function to stop this issue from happening.

The fuel that runs into the cylinders will work its way past the rings and into the crankcase. this dilutes the oil and petroleum makes a horrible lubricant for bearings, so running your engine with the fuel in the oil is almost as bad as running with no oil in the cranksace.

The reason you got oily fuel into the airbox is that is where the crankcase breather line dumps to. With all the gas that seems to have made it into your crankcase, the oil level is so high your pushing oil out the vent (well, oil and gas mixture).

So, first issue is the carb float valves. then worry about petcocks and vacuum valve (OCTY).

+1 replacing the float needles!.......they're bad either way.

[James England]

The faulty petcocks are highlighting faulty float needles/floats in the carbs. As has been said, you should be able to leave the petcocks even on PRIME (which bypasses the vacuum cutoff in the petcock) and still not have fuel flooding out of the carbs. The fact that it's doing so, and filling your airbox and crankcase probably, means the float valves need looking at. It need only be one faulty carb. I doubt it's all four of them.

[Howell4706]

crank case was not full of gas.

i'll be taking the carbs off tonight, anyone have any good youtube videos?

edit: i did watch the above video, it was pretty good just looking for some more. and do i need any special tools? besides micro sized hands