what happens if your engine fills with gas?

[12thmonkey]

This is a purely hypothetical question. There is no way this could have happened to me. Okay, it would be too difficult to write this entire post in hypothetical third-person...so i'll just write what really happened...to me. 

i have a bike that i don't ride very often (long story), and has been sitting for probably close to six weeks without being run. Being the genius that i am, i actually left the bike in prime for that entire time. And apparently, my float heights are off. i pulled the tank a couple weeks ago when i noticed a little gas dripping out of the drain tube from the airbox. i cleaned all the gas out of the airbox, and thought i had fixed the problem, but never put the tank back on. Today, i was going to drain what oil hadn't leaked out already (my drainplug was stripped by the PO ), and was going to put some teflon tape on the drainplug as a temporary fix until i have the time to put the new oilpan on. But when i pulled the plug, a strong flow of oil diluted in gasoline gushed out. Not fun. It knocked my container/funnel over and made a horrendous mess. i got the mess cleaned up as best i could (thanks to my cat for loaning me some of his litter), but now i gotta figure out what to do with the bike.

Did having that much gas just kinda hanging out in my engine for several weeks do any serious damage? If so, what would be most likely damaged? What all do i need to do to get it back up and running?

[pantablo]

what bike is this?? not your gs?

[ducati_nolan]

If you didn't run the bike you're fine. It wouldn't have hurt anything, just make sure your cylinders aren't full of gas and/or oil before you crank it over or you could bend a rod. Pull your plugs and turn it over a couple of times to make sure you get most of the stuff out of the cylinders before you try and start it.

As for your oil pan, you can just drill out your stripped drain hole and tap it out to a larger size drain plug. If you're anal and for some reason want the stock size drain plug, you could even helicoil it. Take off the oil pan first to keep the metal shavings out of the engine though.  A tap is much cheaper than a new oil pan (especially if you can borrow one).

An interesting note on gas getting into your oil, On some airplanes that run with single weight oil (don't ask why, airplanes still use 1930's technology) they have an oil dillution system, which drains gas into the oil to thin it out. Before shutthing down the plane after the last flight of the day, you drain a few quarts of gas into the engine and let it idle for a minute to let the gas and oil mix. The next day when you go to start the engine, the oil is thin enough to pump through the engine preventing oil starvation on startup (have you ever tried to pour 40 weight oil in sub freezing temps? It dosen't flow too fast). As the engine warms up, the gas evaporates and leaves the oil behind.

I have never used this system, but suposedly it's better than starting an engine with congealed oil. Of course you could just use a multi weight oil.
Have fun 

[yamahonkawazuki]

usually well sometimes, a single weight oil is better for certain things

[coll0412]

Yeah it will attack the gaskets but thats really about it. Just make sure that you drain the oil super well and get it all out. Then refill and not forget to turn it off of prime.

Yeah gas in the oil is really dangeous. I once had a small block chevy on a engine stand for testing. I had trouble starting it so I just kept cranking it with full choke. Eventualy it would never start and all the unburned gas went into the oil. Then when I fixed the problem(the ditributor was in 180deg off) and fired up it ran like a dream. Then about two minutes later a big Kaboom and I could see flames should out of the gasket between the oil pan and the block. Fortnantly no damage to anything other than the underwear I was wearing at the time.

Straight weight oil is much better in terms of logevity compared to a multi-weight. They have to use viscosity modifiers(carbon chains)  which curl up into little balls when cold and then when they become long strings when hot to get a mutli-grade.

[ducati_nolan]

Yeah when I was reading about the oil dillution system for the Cessna 182, I was wondering about the possibility of fire, that sounds like it could really suck to have an engine explode in flight.

I know that single weight oils are better for certain things, like long flights where the startup protection isn't nearly as important as the long term protection at continously high power settings. It's also better at protecting against corrosion durring periods of inactivity, since it's thicker when cold and clings to parts longer. It usually withstands high temps better too.

But durring the winter it's usually better to go to a multi weight oil unless you have an oil pre-heater installed, or you park in a heated hanger. I think multi weight oil would at least be better than oil mixed with gas

These are some of the reasons that cars (and bikes) always call for multi weight oils. Usually people have lots of starts and short trips, don't let the engines fully warm up before driving and usually the engines are run at a low percentage of their max power for the majority of the time.

Racers often use single weight oils and heat it up besore they start so they get the protection of the single weight and don't need to wory about it being too thick at startup.

Anyways just ramblig about oil, this always starts an argument