Whats this mean

[bigs_gs]

Ok I just bought a 1980 gs850L and the guy that owned it before me left the fuel petcock in the "prime position" and it resulted in alot of gas getting in my oil. I'm replacing my oil today but is there anything else I need to do before I run it to prevent destroying my engine if it isn't already destroyed.

[chiphead]

If it was me, I'd run the bike 20 miles then change the oil again. But that's me.
Also, if the engine filled with gas from the prime position, the needle and seats that the floats should close to stop the flow of gas aren't functioning correctly. Maybe a piece of dirt or just plain bad luck.

[bigs_gs]

Yeah I probably need to rebuild the carbs now which sucks cause I hate tearing down components with real small parts like that. But the guy let it sit for a really long time in the prime position so hopefully I wont have to. We will see.

[sharpy]

oil in fuel

Wont be a problem after u changed the oil. But just to be safe take out your plugs and put the plug leads away in a safe place and turn the engine over just in case there is fuel on top of the pistons as this will caused a hydraulic lock and bend your conrods in extreme cases. Your carby needle and seats may be stuck/worn also as fuel shouldnt go past them even if the fuel tap was left on. If its been sitting a real long time the fuel has dried in the carbs and left a varnish covering over the needle seats so u might need to strip the carbs. Hope this helps.

[RJ]

Usually when you buy a bike with the petcock set to "pri" it means that the vacuum diphragm in the petcock no longer works and the only way to get fuel to the engine is to place it in the "Prime" position. This position is typically only used to fill the carb bowls with gas, like after you work on the carbs. You can run the bike no problem in this position, you just have to remember to turn it to "run" or "res" when you shut the engine off so the fuel doesn't overflow into the intake and flood the oil with gas. Of course you can rebuild or replace the petcock so you retain the safety feature that only allows gas to flow when the petcock is receiving vacuum from the engine while it's running.

[t3rmin]

The carbs shouldn't overflow if the float valves are sealing right. Pay special attention to the o-ring on the float valve seat.

[bigs_gs]

It was running but the engine wouldnt rev up and it was SPRAYING stuff into the airbox through the the hose that comes from the top of the engine. Also cylinders 1 and 4 were dead until I really gave the plugs a good cleaning. Now its firing on all four but the oil problem (which I just found out) was causing some major isuues lol. Thanks for the help guys..

[t3rmin]

So the "stuff" being sprayed into the airbox is definitely oil? And it's definitely coming from the hose on the valve cover?

[bigs_gs]

Yeah I took the airbox off cause i thought it was gas backing out of the carbs but its a mixture of gas and oil coming from the valve cover. And when I drained the oil there was like 5 or 6 quarts worth of liquid that came out lol.

[t3rmin]

Oh. Well I suppose that could be the result of being drastically over capacity in the crankcase. It's not still happening now that you've changed the oil, is it?

[renobruce]

Also, if the engine filled with gas from the prime position, the needle and seats that the floats should close to stop the flow of gas aren't functioning correctly.

That is unless it leaked through the vacuum line from the petcock. If the float needles fail, the excess fuel should drain out of the overflow tubes. Sounds like your engine was over full from the gas getting into the oil causing the blowby into the crankcase breather tube. Change the oil. I too would change it again after running it for awhile (oil is cheap). I would bet your petcock is bad.

[bigs_gs]

Yeah im pretty sure it is. I took the tank off and fuel still came through the delivery tube. The guy that owned it before me drove it and then let it sit for several months in the prime position (not that it mattered with the petcock in the operating condition its in) and when he tried to take it out it started doing what it is now.

[bigs_gs]

I changed the oil but it still bogs down around 3 to 4k RPMs. It smokes alot and backfires through both the carbs and the tail pipes when you rev it up. Any suggestions on what this might be.

[t3rmin]

Get those carbs cleaned out!

[bigs_gs]

What would cause the smoke though? If it werent for all the smoke I'd almost think it was a timing issue. I dont know how to se the timing on these things though lol.