I left the petcock on PRI overnight...

[WalterGA]

just got my bike (my first GS) and I thought I was setting the petcock to the 'off' position overnight. I started it the next day and rode it for about 10-15 min, realized something was wrong (sluggish performance, a bit of white smoke), came back and learned what the "PRI' position is used for#-o .
I guess fuel must have flowed into the engine oil (the oil does have a fuel smell). So, now what? Change the oil and filter and I'm good to go, or have I done more damage than I know?

[Billy Ricks]

Most likely no damage. Change the oil and check the condition of the float needles. Also check to see if fuel flows through the vacuum port on the petcock with it set to prime. If it does the diaphram is shot. In fact, check the vacuum port for a fuel leak first before checking the floats out.

[WalterGA]

thanks for the reply. I'm not sure I understand, though... isn't fuel supposed to flow through when the petcock is set to prime?

[Billy Ricks]

thanks for the reply. I'm not sure I understand, though... isn't fuel supposed to flow through when the petcock is set to prime?

You have a fuel line and a vacuum line going to the petcock. There is a diaphram in the petcock that if it gets a hole or tear in it will allow fuel to flow through the vacuum line and into the carb the vacuum line attaches to when on prime.

[twistedwankel]

Prime

The prime is only supposed to be used for when the bowl of the carb has been sucked dry like when running out of gas to speed up the re-starting process. Or after being stored off season. It bypasses the vacuum actuated (normally off) setting of run and reserve. Kind of brilliant I think.

Your floats probably leaked by a little so probably no harm done?

You will find out when you run it again with new oil over time.

[Buffalo Breath]

The Flood

Pull your spark plugs and check them you may have soaked one, the gas smell is normal in the oil for the most part a factor of ring blow by, you need to check the oil level to see how much it is over full with gas, when in doubt change them out (replace)

[WalterGA]

thanks for all the info. I'll check my plugs, check that the petcock isn't leaking, and change the oil.

Found this for reference:

...to tell for sure if your oil is saturated with gasoline, place a drop of it on a piece of corrugated cardboard box and observe. If there is gasoline in the oil, the gas will be rapidly absorbed by the cardboard and quickly make a large darkened outer ring around the drop of oil. If there is no fuel in the oil, it will slowly soak into the cardboard with no apparent outer ring. Crank case oil can sometimes smell like gasoline but not actually be diluted.

[Road_Clam]

Pull your spark plugs and check them you may have soaked one, the gas smell is normal in the oil for the most part a factor of ring blow by, you need to check the oil level to see how much it is over full with gas, when in doubt change them out (replace)

Gas smell in the oil is NOT normal. The reason his oil smelt like gas is because raw excess fuel flowed into the cylinders, past the pistons/rings and down into the crankcase.

[Road_Clam]

thanks for all the info. I'll check my plugs, check that the petcock isn't leaking, and change the oil.

Found this for reference:

...to tell for sure if your oil is saturated with gasoline, place a drop of it on a piece of corrugated cardboard box and observe. If there is gasoline in the oil, the gas will be rapidly absorbed by the cardboard and quickly make a large darkened outer ring around the drop of oil. If there is no fuel in the oil, it will slowly soak into the cardboard with no apparent outer ring. Crank case oil can sometimes smell like gasoline but not actually be diluted.

You most likely have worn out carb inlet needles/seat(s). Your engine will be fine. (if anything you gave your engine a fuel "sludge cleaning" from the raw fuel. LOL

[riskadh]

I had the same problem on my bike a month back or so. It filled up the crankcase so much, it was stalling out the bike. But thanks to some help from the wise peeps on this site, and a change of the oil, hooked the vacuum line up and the bike has been running great since with no problems. ](*,) <knock on wood

[WalterGA]

I had the same problem on my bike a month back or so. It filled up the crankcase so much, it was stalling out the bike. But thanks to some help from the wise peeps on this site, and a change of the oil, hooked the vacuum line up and the bike has been running great since with no problems. ](*,) <knock on wood

Just read your thread. what a great forum this is

[WalterGA]

Update:
Changed the oil, changed the plugs (all four were very black) and it started right up. I let it warm up, took a ride around the block and besides a few tiny pops emanating from the engine block (residual fuel?), everything seemed fine. I'm going to change the oil again after riding for a day or two, just to be sure.
Thanks again for everyone's help