Engine Oil in the carbs

[MNBikerPup]

Hey guys, been a part of DTT for awhile now. And now I have a dilemma. I have a 2004 Yamaha V Star 1100 Classic and twice now when the fuel ran low of a gallon or so, the engine would stall under throttle. Idle no problem for the most part. So, today I took the bike down to run some seafoam through it and I discovered engine oil in the carbs. Not cool. I have my theory that the piston rings are failing if not already failed, but I wanted to run it by you guys who have way more experience in motorcycle engines. Also, if this is the case, aside from replacing the piston rings what else should I expect to do with the rebuild of the engine? Thanks. All help/advice appreciated.

 

[hotrodcharlie]

How many miles are on the bike?

 

[Sonreir]

If it is oil, it's probably not piston rings. It's probably valve stem seals. But even then, having oil travel all the way up the ports and into the carbs would be a tough thing to happen. I think it bears further investigation.

I'm assuming you're blowing all sorts of blue smoke?

 

[hillsy]

More than likely it's blowing oil through the crankcase breather back into the airbox. Happens quite a bit on big twins (my Intruder does it after a long hard ride). Especially likely if the oil level is too high as well.

Have you checked the airbox for oil?

 

[MNBikerPup]

Yes, there is oil in the airbox. I also noticed oil on the air filter as well. The engine currently will idle but choke out under throttle as well. Little history, the bike sat for about 6 weeks with less than a gallon in the tank (Not my doing, but someone who I thought was a brother) and it was discovered that it gelled on me, got that cleared up and no issues till a week ago when the tank is a gallon or less full.

 

[MNBikerPup]

The bike has 35K miles, 17K of which were on the bike when I bought it two years ago. I have done the oil changes and sta bile for the winter time, even though for the most part I operated in winter on clear roads. No blue smoke. LOL Hence why I posted on here before assuming.

 

[hillsy]

If the bike is running and there's no smoke signals coming out the exhaust then the oil is getting into the carbs from the airbox......not from the motor side.

Do a compression test next to check the state of the rings. Then check the blow out of the crankcase breather.

Worst case scenario it needs new rings or it could just be stuck rings causing excessive blow-by.

Or it might just be overfull of oil......

 

[Scruffy]

In order, the most likely issue is...
A) Over filled crankcase.
B) Faulty breather causing excessive crankcase pressure,
C) Carburetor with a sticky float dribbling gasoline through the intake and into the crankcase, causing an overly full, overly pressurized sump.

Check your oil level. Give it a sniff.