Gasoline in the Oil Pan

[theLeopard]

Alright I got my carb cleaned and my overflow hoses aren't leaking.

but I've changed my oil twice in two days and I am smelling gasoline in the oil.

Two questions:
1) what does this do to my motor/scooter?
2) what is the cause(s)?

[fintip]

1. It causes poor lubrication, making the oil too thin to be effective, substantially increasing wear on the engine. You do not want to run the engine until you have this resolved.

2. Overflowing carbs. Someone else should chime in, because as far as I know, if you're getting oil in the oil pan, it's because your carbs are overflowing, and so one would expect your overflow hoses to be dripping. It is likely not because something isn't clean, but because your needle seats are worn. Need some new parts in there.

What year bike do you have? Petcock is another culprit on 87 and earlier bikes, fuel pump on 88 and later bikes--both of those, respectively, should be stopping the fuel flow from overflowing in the carbs. (To some degree, that might not be true in a fuel pump model, I think, but I'm not sure--again, someone else should chime in.)

[theLeopard]

it's not the carbs.
I just had the carbs cleaned and installed new rings and needles.

I did a few basic searches and it's looking like a bottom-rebuild; piston rings.
is it a bottom-rebuild?
be blunt, I hate unnecessary nuance.

[giantkiller]

Your petcock is not shutting off the flow and the floats not stopping the flow. Fuel is flowing into the intake. Past the rings and into thecrank case. At least that is what happened to my 86. Twice filled the crank. Once before Iinstalled the manual petcock. And once when Iforgot to turn it off. Had just rebuilt the carbs with Randy's carb kits. Worth checking.

[theLeopard]

but I don't have a petcock.... I have a square nut connected to the gastank-line...
ugh I wish I was better at this. you guys rock, thanks for the replies i'll listen to everything you have to say.

it doesnt' leak from the overflow hoses when running or parked, only a few drops if it idles dead.

[racerrad8]

Is there a fuel pump on your bike?

The solenoid you kept showing in your pictures was carb vent solenoid?

Fuel getting into your engine is coming through the carbs.

Randy - RPM

[Capn Ron]

Yeah, the *only* place gasoline can come from is your carbs.  Don't panic though.

I bought a 1982 Yamaha Seca 550 brand NEW in 1986 as a leftover model.  They just assembled it out of the crate and I picked it up with 2 miles on the odometer.  Because the bike had been sitting for four years, a fine surface rust had built up in the tank and when that rust "grit" flowed into the carbs, it prevented the needles and seats from seating.  Being a gravity-feed bike, the fuel kept trickling past the seats and into the combustion chamber.  From there...over the course of a couple of days, the gas worked its way around the piston rings and filled up the crankcase.

The solution was to drain all that out of the engine and clean out the gas tank...OH and I had to get in the habit of manually switching OFF the petcock when I parked the bike.  Which brings me to your fuel-pump model FJ.  You don't fiddle with the petcock at all on the later FJs.  The fuel pump...when no power is applied...should stop the gravitational flow of gasoline for you.  There's your first thing to check.  Pull the fuel line from the carbs and drop it into a bucket (or whatever else you have handy)...then let it sit overnight.  In the morning if the bucket has fuel in it, your fuel pump isn't doing its job.

You should view the needles and seats in the carbs as a secondary mechanism to stop the gravitational flow of fuel.  Sometimes they get stuck open...Sometimes there's a little grit from a rusty fuel tank preventing them from sealing properly.

I've been following the trials with your FJ and it seems like you're getting her in good shape...Just keep working on the little issues...keep asking what seem like stupid questions, keep up the great attitude and we'll have it sorted in no time.   

Cap'n Ron. . .

[Pat Conlon]

It helps us when you tell us, or remind us, of what model FJ you have....there are differences between them.

Go to your profile page and put the info in your signature line.

[Capn Ron]

It helps us when you tell us, or remind us, of what model FJ you have....there are differences between them.

Go to your profile page and put the info in your signature line.

I'm with you Pat...I had to go back through his older posts and figure out that it's a '92...THEN, I could take a stab at what the issue might be.  I also recalled that he's in San Diego...I would think the WCR would put him on the fast-track to getting things resolved!

"The Leopard"...if that IS your real name...  Care to join us all up in Willits in two weeks?   

Cap'n Ron. . .

[FJ_Hooligan]

Do you just smell gas?  Or is fuel really overflowing into your crankcase? 

You may smell gas fumes because of the vent hose between the case and the airfilter box.  So don't panic until you verify that gas is actually getting into the oil.

but I've changed my oil twice in two days and I am smelling gasoline in the oil.

[theLeopard]

Alright, lots to tackle here in this post so I'll do my best to keep everyone up to speed.

Currently I'm not leaking anywhere. No fuel overflows or leaks, oil seems alright. Probably need to drain the system and replace the filter so I can get a clean whiff on the tank but oil in my gas isn't my immediate problem.

I couldn't service the pilot jets when I serviced the carb, so that's still on the list.
Carbs are clean.
Hoses properly connected.
No noticeable leaks.
Need to recheck the needle-height (there are instructions in my book and here).
Manifolds are old and need replacement but, currently, don't appear to be perforated (just cracking).
Battery is new, and charges.
Fuel pump seems to work, charges when I start the bike and no leaks as previously mentioned.
Throttle works, engine sounds terrible; probably needs to be torn apart soon. Revs good but doesn't sound anything like it did when I purchased it (last week  )
Various hoses need replacement (aged and the tank-solenoid has a small leak in the bridge hose between the solenoid and manual-petcock).
Need to inspect, and possibly service, the spark plugs.

My immediate problem is the bike isn't idling properly.
I pull the choke, it will warm up for a few minutes then the RPM's waver between 2500-3000 and eventually the bike dies. Like it's getting an inconsistent fuel supply.
Smell of gas is noticeable while it idles which makes me think it's running rich, but i'm a novice so maybe that's normal.
I even got a single backfire when I restarted the motor today, shut it off when it died the 2nd time.
Not really sure where to start myself, so many things need replacement.

Randy,
My manual showed up today. The cylinder in question is part to the emissions system and is found in the supplementary service manual FJ1200ADC (pg 101 - H).
It's part of the emissions system but i'm not sure what it does. that niplle you see on the backside (nearest the electrical box) is hoseless and goes to atmosphere. Doesn't leak. I doublechecked the hoses as best I could from the book and they seem to all be properly connected, same as your analysis from the photos.
Heres the image from the book:


Pat,
Noted, and added. 

Hooligan,
I'm fairly certain it's in the oil. I drained the pan last night and dipped my fingers in it, let my roommate give it a whiff. He smelled gas too, just on my fingers, so I'm pretty sure there's gasoline in the pan.

Ron,
I'm concerned the piston-rings are shot and i'm getting blowback, but rebuilding the engine is the last thing i'll attempt. Carbs first.
Thanks for the vote of encouragement, I'm steady but the previous owner didn't take care of this bike at all and I'm backed up at least two-years-worth of service. Daunting.
I would love to join the club up there but my bike isn't running and i'm having trouble finding another job (2months out) so repairs will be slow-going

[FJ_Hooligan]

I couldn't service the pilot jets when I serviced the carb, so that's still on the list.

My immediate problem is the bike isn't idling properly.

I pull the choke, it will warm up for a few minutes then the RPM's waver between 2500-3000 and eventually the bike dies. Like it's getting an inconsistent fuel supply.

These issues are all related to carbs that aren't clean.  Specifically the idle circuit.  Do it right or do it again, and again, and again...

[andyb]

I couldn't service the pilot jets when I serviced the carb, so that's still on the list.
Carbs are clean.

No, they aren't.  

That's like saying I'm not broke, I just don't have any money.

Gas in your oil will destroy the lubrication properties of the oil.  This is going to kill the head, tear chunks out of the cams, and destroy your ring seal.  Fix it, or you'll be needing a full rebuild.  Yes, it's your primary problem.  Hopefully you've not damaged anything yet.  And having the carbs actually clean, along with a tank that delivers clean fuel to the carbs, will fix the majority of your problems as you see them.

Step one is to pull the carbs off.
Step two, while they're off, is to do a compression check.  Leakdown would be good as well.
Step three is to clean the carbs completely and properly.  Write down the jet sizes that you find in them, as you'll be ahead when you need to make changes (for example, going to a different pilot to improve the idle and cruise qualities).
Step four is to drain the fuel tank into the lawnmower, watching carefully for  nasties in the fuel.
Step five is to look for rust in the tank--it'll either clog the screens in the carbs (if you have them, and you'll know, because you've had the carbs apart completely), or it can prevent the float needles from seating.
Step six is an oil and filter change.
Step seven is to reassemble things, and add gas that is no more than a day out of the pumps at a reputable gas station.
Step eight is to synch the carbs.

As you do these things, report back if you run into trouble.  All of these things are pretty well covered in any of a multitude of posts here.

The FJ does not suffer fools in a couple places.  One of them is the pilot circuit.  Another is cheap chains.

[simi_ed]

The FJ does not suffer fools in a couple places.  One of them is the pilot circuit.  Another is cheap chains.

Well said, Andy!  

[Capn Ron]

The FJ does not suffer fools in a couple places.  One of them is the pilot circuit.  Another is cheap chains.

Well said, Andy!  

Yep...brilliant!   

Cap'n Ron. . .