Gas in Crankcase

[junior varsity]

Just want to check before I go assuming:

Picked up a 'project' 99 M900 for shits, it needs a lot of work, perhaps when running (and safe), the wife my practice riding on it in the parking lots before we get her something 'just for her'.

I can list all the other things it needs or will be getting done to it, but starting with draining the oil - it ran out brown like water. Smells of bad old oil, and I believe gasoline. My thoughts were immediately, gas in crankcase is probably a bad vacuum petcock - not turning off, flooding motor with gasoline.

Thoughts?

Bike details: 1999 Ducati Monster M900. W-heads. FCR Carbs. OEM Mikuni Vac Fuel Pump, OEM Vac Petcock, all OEM fuel/vac lines. P/O had fuel line originally connected to top nipple on FCRs, which, if I am correct, is supposed to be the overflow. A vent/overflow line was connected to what I believe is the normal fuel-in connection. Not sure how long it was like that.

Previous owner exercised 'much neglect', so far I've gotten to replace sprocket carrier and swingarm (chewed up), forks (bad seals), front tire (bald. flat.), steering head bearings, sprockets, sprocket retaining plate. Will need or am going to replace fuel filter, fuel lines, oil cooler lines, brake/clutch lines, brake pads, perform valve/belt service, battery, plugs/wires/coils, starter/ground wires, exhaust manifold gaskets, flush/bleed all hydraulics, investigate taboo wiring job. Itsa gonna takea while-ah.

[Porsche Monkey]

My vote is for the petcock but I don't run one on my 900 anyway.

[ducpainter]

<snip>Itsa gonna takea while-ah.

Yeah...

but none of it is rocket science.

Sounds like you know where to look...

and you gotta love carbies.

[junior varsity]

ha, indeed.

*My* M900 just uses a simple manual on/off.   But also, I haven't neglected maintenance duties on it either.

[greenmonster]

Stuck float.
Bad vacuum petcock shouldn`t pass fuel to case if float works good.
But petcock could be bad anyway.
My 2c.

[Rock Store]

am, Lower T nipple is fuel feed & upper T for venting.The way their connected now is absolute 0 fuel delivery to the bowls.
later..RS

[koko64]

Yeah, filthy old fuel under the float needle, but you'll flush out the carbs anyway. Old vacuum petcock is probably not in good shape and not helping, leaving the float needles to do all the work.
Sounds like the engine may have flooded with fuel due to the fuel coming into the carb the wrong way. It may have come down the carb throat. Does the overflow system work this way? I'm away from the bike to have a look.

Will be interesting to see what you think of W heads compared to V heads.

[Howie]

Pull the vacuum line to the pump and look for fuel.  It should be dry.   

[greenmonster]

Pull the vacuum line to the pump and look for fuel.  It should be dry.

Can fuel pass through the vac pet that way?

[mookieo2]

Should be a clogged or worn float valve. clean and rebuild the carbs. Its pretty simple.

[Howie]

Can fuel pass through the vac pet that way?

No, but it can pass through the diaphragm in the fuel pump while the bike is running.