Gas(Fuel) Draining into Oil Sump

[Rockers]

This has happenned twice in the last 2 years to my 1987. After the bike has been sitting for a while and I take it out for a ride, the oil sump is full of a gas and oil mixture. This first time it blew a bunch of the mix out and onto the rear wheel. Yesterday the sump was full and prevented the bike from restarting after a 10 mile run. I noticed the repeat problem after the bike wouldn't start.

Has anyone else seen this problem with their Paso or Ducati? Did you come with a good premanent fix?

Thanks
Bob

E-mail me at rockers@centurytel.net

[ducinthebay]

Yes, I have seen it before. Your float is sticking and flooding your carb when parked. The fuel is running past your valves, and past your rings into your crankcase.

- Adjust your float and put in a new needle valve.
- Use the fuel petcock.
- get a new fuel pump that doesn't let the fuel run past it when stopped.

if it happens, you need to change your oil, as it will be too thinned to be effective. Don't ride it that way. You will be replacing more than just the bits above.

Cheers, Phil

[Fraser]

Bob,

This happend to me last year. The carb float gets stuck which lets the fuel past and into the crankcase. The oil sight glass would show the oil level to be "overfull", but after a ride the oil level would be too low. This caused some head scratching until our web site here suggested that petrol was draining into the sump. Once you know that you can smell petrol in the oil and if you drain out some of the oil it is very "watery".
No great problem, just give the carbs a thorough clean and change you oil.
Cheers,
Fraser.

[ir_joep]

Happend to me also. Luckely I smelt the fuel and checked. Otherwise the oil would have been to thin and would have ruined the engine.

I think it was due to the infrequent use of the bike which left some residue on the weber's valve. I cleaned the valve and now I make sure that I close the petcock every time!

Good luck Joep

[whitepaso]

Ironically this just happened with me this past week as well. I never shut the petcock off and had no idea it was happening until my engine "vented" the last of the good oil out the crankcase vent and all over the rear end, including my rear tire. I was suddenly alerted to this condition when the rear tire lost grip in a very tight and fortunately slow left hander It could have been so much worse; I am very lucky. I literally wiped the oil off my tire with a rag and limped another mile to a parking lot where I could park the bike to be picked up.

I'm running Dellorto carbs with stock fuel pump and the crankcase vents through a K&N filter right near the battery case. Carbs were thoroughly rebuilt in 2009 so am surprised this has happened now in the all the years I've owned it.

I just drained the oil and its loaded with gasoline so I'm planning to pull the carbs and clean them and seats. Am also planning to undo the oil radiator hoses to drain them. As for gasoline in the oil, is it enough to replace the filter and simply fill with fresh oil and run? Or is there something else to do? I'm assuming start and run engine for a few minutes, then drain oil and replace oil and filter again? What else am I missing?

[ahdoman]

How do you guys close the petcock? Do you take the side panel off every time? I've always done this with all my other bikes but I can at least get to them.

[whitepaso]

I don't see any other way to do it myself.

[ducinthebay]

One possible solution is to install a vacuum operated petcock. They came stock on some Monster models and are generally cheap on e-bay, if someone accurately described it and new what it was when they disassembled the bike. They are an inline petcock, and and have a mounting bracket, so they don't replace the current petcock on the tank.

Many of the Hondas in the 70's and 80's had vacuum operated petcocks on the tanks. Of course they failed after 15 years, which caused a lot of problems and distrust of the practice. The diaphram would break and it would no longer function correctly. People would try to bypass them instead of replacing the worn parts and thing got ugly quick.

Cheers, Phil

[Clint750]

Or...you could get out your hole saw and create access Frankenstein Paso style. Petcock is a proper on-off-reserve type. I forget where I bought it. Guzzi I think.

BTW, coil cover is a TV dinner tray!

[20YearOwner]

I have a 1987 which I purchased new.

The problem you describe occurred to me. The fuel today has alcohol in it which attacks all the rubber parts of the fuel system.

I purchased a carburetor rebuild kit from Weber part # 92.1153.05 for $56 US dollars and performed the rebuild myself. This ended to problem.

When I had the carburetor off me also replaced the fuel lines, fuel filter including the vent tube line on the underside of the fuel tank.

[jayh]

You could put an elbow at the tank outlet and route the hose back through the front of the seat cavity with an inline tap.

This has the added advantage of being able to rotate the tank 180 degrees and sit it where the seat was when working in the upper engine area,without disconnecting the fuel line.

I have also put a battery isolator switch in front of the battery box on mine,pop the seat up and shut off fuel and battery easily. J.

[whitepaso]

Hey jayh,

Do you have a photo or two you can post?