V50ii fuel in sump

[Scout63]

I’m trying to solve two issues with my v50ii - dragging clutch and the right cylinder not firing. When draining the crank oil I found it heavily contaminated with fresh gasoline.  Could this be a result of the cylinder not firing and just pumping unburned gas to the crank?  I’m wondering if it is pumping through the cylinder breather directly to the sump?  I’ve pulled the drivetrain and separated the engine and transmission so that I can check the clutch.  The bike has about 7600 mi on it but sat for many years.  I will pull and look at the cylinders, pistons, heads and valves and check timing. Just to make sure I’m upside down on the bike I ordered a Sachse ignition that I will install during reassembly. Any ideas will be welcomed.  Thanks,  Ben

[Harley PHD]

  Gas in the oil can cause it to foul sparkplugs.  The way the crank turns it could affect one cylinder more than the other.  The stock ignition is so bad Guzzi went back to points on the V50III.  I converted my V50II to dual sportster ignition modules with Harley ignition pickups.  Made an rotor out of a washer.  Make sure to get the right ignition set up.  Yours is crank triggered, not points.



  Usually gas in the oil is from a bad needle and seat in carb and gas drains in past rings when parked.

[moto-uno]

 ^ You are one handy dude  . Peter

[guzzisteve]

PHD---That is thinking out of the box. At least you can get parts.

The fuel issue is cylinders getting washed from no spark & leaking needles if you don't shut off fuel taps when not running.

[egschade]

It's not the needles - it's the float valve & seat. Most have a small rubber seal on the valve which deteriorates with age and allows gas to seep past the seat. Turning off the petcock will work but sounds like a carb rebuild is in order.

[lucky phil]

I’m trying to solve two issues with my v50ii - dragging clutch and the right cylinder not firing. When draining the crank oil I found it heavily contaminated with fresh gasoline.  Could this be a result of the cylinder not firing and just pumping unburned gas to the crank?  I’m wondering if it is pumping through the cylinder breather directly to the sump?  I’ve pulled the drivetrain and separated the engine and transmission so that I can check the clutch.  The bike has about 7600 mi on it but sat for many years.  I will pull and look at the cylinders, pistons, heads and valves and check timing. Just to make sure I’m upside down on the bike I ordered a Sachse ignition that I will install during reassembly. Any ideas will be welcomed.  Thanks,  Ben

Its probably got a leaking float needle and seat on the carburettor on the right carb. The leaking float needle and seat will let fuel migrate into the r/h cylinder and into the crankcase when the fuel tap is left open and will also cause flooding to that cylinder when running which could be the cause of the no combustion drowning the spark.

Ciao

[Chuck in Indiana]

^^^^ Wat Lucky Phil sez.

[Scout63]

Thanks for the feedback. I just fully rebuilt both carbs but I’m going to check the float needle and seat on the right side. When riding the right cylinder was cutting in and out so I thought intermittent ignition not burning fuel when the cylinder was dead.   I’ve been careful to keep the petcocks closed when not riding.

Is it possible for the head breather pipes to flow unburned fuel to the sump?  I would think not. I have a sachse ignition on order.  The pickup wires are pretty corroded- Maybe a bad ground. So many ways to fail.

[lucky phil]

Thanks for the feedback. I just fully rebuilt both carbs but I’m going to check the float needle and seat on the right side. When riding the right cylinder was cutting in and out so I thought intermittent ignition not burning fuel when the cylinder was dead.   I’ve been careful to keep the petcocks closed when not riding.

Is it possible for the head breather pipes to flow unburned fuel to the sump?  I would think not. I have a sachse ignition on order.  The pickup wires are pretty corroded- Maybe a bad ground. So many ways to fail.

How much fuel is in the oil?

Ciao

[Scout63]

A lot. Smells strongly of gas, flows easily when cold and pretty clear.  I should have measured it but I put the pan outside to let the gas evaporate out.

[lucky phil]

A lot. Smells strongly of gas, flows easily when cold and pretty clear.  I should have measured it but I put the pan outside to let the gas evaporate out.

That sound like more than an engine that's simply misfiring and periodically running on 1 cylinder. Is your fuel tap shutting off perfectly? are your float heights set correctly and are the carb needle and seats sealing?
If the float heights are wrong or the needle and seats are leaking and the fuel tap isn't shutting off perfectly you can fuel up the crankcase oil.

Ciao

[Scout63]

Update on this issue.  After crabbing the frame and sorting a sticky clutch pushrod, installing a sachse e- ignition, pulling the heads and cylinders and cleaning everything up, installing a new rotor/stator/ diode board/ regulator and putting everything back together, the bike still didn’t run right and was washing fuel into the right intake manifold.  I opened up the right carb and found that I had forgotten to install the idle jet when cleaning the carbs last Spring.   It must have been pumping raw fuel up from the float bowl through the idle jet housing, flooding the spark plug and washing fuel into the sump.  I ordered a new jet and hopefully it will be solved. At least now I have a spotless and fully refreshed v50. Another lesson learned.

[moto-uno]

  Wouldn't have considered that , so tell us about your work habits  . Just kidding , Peter

[Scout63]

Usually I’m pretty careful Peter but this mistake is inexcusable. I’ve gotten out of the habit of sketching assemblies when taking them apart.

[Wayne Orwig]

Usually I’m pretty careful Peter but this mistake is inexcusable. I’ve gotten out of the habit of sketching assemblies when taking them apart.

Cell phone camera is great for that kind of stuff.

[Chuck in Indiana]

^^^Yep, that's why the Goddess invented cell phones..