Gas in Oil

[chefmatt]

Hey All -

Tonight we had a break in weather (SNOW in forecast this WEEK...sh*t) went for a ride on my  '89 and noticed my crankcase breather was smoking furiously. The breather is on the end of 2 foot length of hose attached to the rear set (UNI Pods installed) I reached down and let the vapor smoke on my glove for a sec, took a sniff, and smelled very strong fuel odor. The smoking breather is a usual occurrence, albeit not as much as tonight, especially after running hard. The fuel smell is new. Just did an oil change about 500 miles ago, and it wasn't there then.

Sooooo fuel is getting past the rings. Time for a carb rebuild?? Doing an oil change ASAP, but is this a waste of money? I have had intermittent drip from carb, probably stuck float valve..... Has fuel in oil happened to anyone? The loss of lubrication will likely break down an engine quick fast in a hurry. Any help appreciated.

Regards, Matt

[Pat Conlon]

Yep, very common to have debris/residue on your float needle seats, that would cause a noticeable pisser when the engine was running and the fuel pump was pumping....however, first check your fuel pump.
With the engine off, disconnect the output side (line to carbs) and see if any fuel is dribbling through...there should not. If there is, then consider fixing that first (new pump) then addressing (cleaning) your float needle seats. Also consider installing a fresh fuel filter.

These 2 things happening together can be a silent killer. Happening to your bike while parked. A leaking fuel pump and leaking float needle seats. You can dilute your gas (as you know) or even fill your entire crankcase up with fuel then having it hydro lock on you when you thumb the starter...expensive things break that way.

It is a hard lesson, but consider yourself lucky.

Ethanol laced fuel sucks.

[Tuneforkfreak]

Had this happen to me many times on other bikes, Yamaha ATV's where notorious for it in mid 2000. If guys had a no fire on a Kodiak the dipstick was the first thing to check, I'd have guys saying why are you checking the oil? I'd say I'm not! I'm checking the gas! One things for sure, Pat hit the nail on the head! Time to go through and freshen things up before it does you wrong.

[Charlie-brm]

Funny you mention the ATVs. I set off today to help someone pull the starter motor from their Yamaha Big Bear, made in the late nineties.
Getting the starter out, easy peezy. What I was not ready for was the gusher of gas-oil coming out the hole as I pulled the unit from the engine. Over a liter for sure. I was pretty embarrassed for a few seconds that I didn't know ATV's ran "wet starters", LOL.
Now I guess we're side tracked into getting a float seat kit. I've never seen a gas-oil situation on a motorcycle thank goodness but I sure got a sample from that ATV today.

[Tuneforkfreak]

Yup, now you too have experience with it. When you don't know about this, and you're trouble shooting a non starter it can baffle you. When you have spark, compression and fuel and it still won't fire it can drive you crazy. It's the true meaning of flooded and with all those fumes in the crank case it simply can't run.