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       #Post#: 2539--------------------------------------------------
       Petrol in the engine oil
       By: Dunders Date: February 9, 2019, 8:59 am
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       Hi, all,
       In autumn, Bossom decided to pour petrol all over the garage
       floor.  Since then the carb has been on the workbench till a
       couple of days ago, when I rebuilt it after a good clean and
       refitted it.
       Today I took the bike off the lift, put a gallon of fuel in the
       tank and she started first time under choke.  She wasn’t very
       smooth, but I needed to adjust the carb.  Couldn’t get her to
       run smoothly at all, even when warm, so I thought I’d put her
       back on the lift and drop the oil, clean the plug and think
       about the timing.  After all, I keep hearing that most fuelling
       problems are electrical………
       So I put the drain bucket under the sump and loosened the filler
       bolt.  Black, thin liquid smelling of petrol started to gush out
       (all over the exhaust, which made me look for the fire
       extinguisher!).  So it wasn’t electrical…
       I drained 5 litres out of her.  There should have been 3 of oil…
       It was *very* thin, so I wonder if she’d been burning oil
       latterly.  No black smoke that I can remember, but?  I did check
       the oil regularly, so it would be a late development.
       I’m hoping 2 things: one, that the petrol got in there at the
       time the float stuck and p*ssed petrol all over the floor, and
       two that I haven’t damaged the engine internals.
       Once the smell of petrol has diminished in the garage I’ll go
       and see if the fuel is getting through to the engine now (I
       clamped the petrol line to stop any leakage whilst it was
       erupting from the filler: I couldn’t remember for certain which
       way the petcocks turned for off!).  If not, then I’ll hope that
       the fuel got in there earlier and that no damage was done.
       Should I be looking/checking elsewhere?  This has never happened
       to before, so I've never had to deal with the fall-out.
       Thanks!
       Paul
       #Post#: 2541--------------------------------------------------
       Re: Petrol in the engine oil
       By: banquo Date: February 9, 2019, 5:45 pm
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       If the float's been stuck down, and you left the tap on, then
       yes, the fuel will continue to flow, and quite happily follow
       gravity down through the inlet manifold and into the sump via
       the cylinder. If you drained it, and refill with fresh oil, it
       shouldn't do any harm. People used to mix petrol with oil in the
       early days, for easier starting in winter. Not recommended, but
       they did...
       Taps are off with the lever horizontal, but the seals are
       readily damaged by modern fuel, and they will leak eventually.I
       kept mine to a minimum by dispensing with the right hand tap
       altogether, and blanked that outlet off with a threaded plug and
       washer, so I have only one to worry about, and no t-piece.
       If it were me, I'd change the oil again after a couple of
       hundred miles, You won't have got all the contaminated oil out
       by dropping the sump oil, as much will be left in the timing
       chest. As oil's much cheaper than an engine issue, for me it
       would be good insurance to change it again.
       You're not alone; I read years ago of someone with a Suzuki
       2-stroke T500 who wrecked his engine when his diaphragm fuel tap
       failed, filling the crankcases with fuel. First kick threw the
       fuel into the cylinder, where it formed a hydraulic lock, and as
       he jumped up and down on the kickstart to try and free it off,
       having no idea what had happened, he bent a con rod, and needed
       a rebuilt crankshaft
       #Post#: 2544--------------------------------------------------
       Re: Petrol in the engine oil
       By: Dunders Date: February 11, 2019, 4:40 am
       ---------------------------------------------------------
       [quote author=banquo link=topic=395.msg2541#msg2541
       date=1549755903]
       If the float's been stuck down, and you left the tap on, then
       yes, the fuel will continue to flow, and quite happily follow
       gravity down through the inlet manifold and into the sump via
       the cylinder. If you drained it, and refill with fresh oil, it
       shouldn't do any harm. People used to mix petrol with oil in the
       early days, for easier starting in winter. Not recommended, but
       they did... [/quote]
       Thanks for the re-assurance.  These things are mostly robust,
       and it hasn't been under stress, so I'm hopeful all will be
       well.
       [quote]Taps are off with the lever horizontal, but the seals are
       readily damaged by modern fuel, and they will leak eventually.I
       kept mine to a minimum by dispensing with the right hand tap
       altogether, and blanked that outlet off with a threaded plug and
       washer, so I have only one to worry about, and no t-piece.
       [/quote]
       That's a thought for the future.  I had the taps out for a
       clean, and they are not the originals.  They have a reserve
       position, but it's not marked on the tap(!).  I *think* that the
       RHS is forward for off, down for on back for reserve, the LHS
       obviously vv.
       I'm waiting for some crush washers (the sump plug was sealed
       with a red gasket-in-a-tube substance) - 45mm id is not a common
       size - so I left both taps 'on' yesterday afternoon and there's
       now no sign of fuel dripping through, so the rebuild of the
       carbs must have worked.
       [quote]If it were me, I'd change the oil again after a couple of
       hundred miles, You won't have got all the contaminated oil out
       by dropping the sump oil, as much will be left in the timing
       chest. As oil's much cheaper than an engine issue, for me it
       would be good insurance to change it again. [/quote]
       Thanks.  This is good advice and I wouldn't have thought of this
       myself.
       [quote]You're not alone; I read years ago of someone with a
       Suzuki 2-stroke T500 who wrecked his engine when his diaphragm
       fuel tap failed, filling the crankcases with fuel. First kick
       threw the fuel into the cylinder, where it formed a hydraulic
       lock, and as he jumped up and down on the kickstart to try and
       free it off, having no idea what had happened, he bent a con
       rod, and needed a rebuilt crankshaft
       [/quote]
       Nothing's new, though even at my age too many things are new to
       me!  I've heard various similar horror stories, which is why I
       thought I'd ask the group.
       Thanks again!
       Paul
       #Post#: 2545--------------------------------------------------
       Re: Petrol in the engine oil
       By: banquo Date: February 11, 2019, 7:18 am
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       No bother Paul
       #Post#: 2607--------------------------------------------------
       Re: Petrol in the engine oil
       By: krisztian_andre Date: April 14, 2019, 8:37 am
       ---------------------------------------------------------
       Mine needs to be rebuilt because of this, but I rode it for a
       thousand km with the crankcase full of petrol.
       In your case I think anything will happen and if something has
       worn out then you'll hear it.
       Br,
       Kris
       #Post#: 2611--------------------------------------------------
       Re: Petrol in the engine oil
       By: Dunders Date: April 29, 2019, 11:22 am
       ---------------------------------------------------------
       Thanks, Kris.  All is well, I think, and no permanent damage
       done.
       I ran the NF for about two hours in total at pretty well full
       throttle at the VMCC test day a couple of weekends ago, and it
       didn't miss a beat.  The day showed that some jetting work is
       needed, but that's now in hand.
       Paul
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