Getting Gwen the Mini to Run.

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As I say, I cannot find anything specifically wrong with the OLD SU pump diaphragm I just put on there, but have put a cheap brand-new pump on for now.
Ah so it's an electric SU pump.. no connection to the engine/sump then. So petrol can't be in the oil.
Other than unburnt girl getting past the rings while it's on choke.
Get it nice and hot.. any petrol will burn off in no time
 
Indeed, I am going to siphon off a sample of the oil and see if it is easy to set fire to. :)
I think you'd need a lot for that. I bet you don't need much at all to make it smell of petrol. Think about it, when you get petrol on your fingers, the smell lingers when you've washed them!
 
It is "stupid question" time again folks. :D
And probably an overly long post that can compete with one of @Stanleysteamer 's tomes.
TLDR/ Version...is there a simple test to detect the presence of petrol in oil?
Why?
Having fixed the "fallenoff" exhaust (special German make I believe ;) ) I took her for a spin and all seemed well except for a couple of misfires under heavy load up the hill at 50.
I got home and opened up the bonnet to see that the car was ticking over and the newly installed inline petrol filter was more or less empty of petrol and you could see the incoming squirts of fuel from the pump arriving into the filter.
That's ODD, I thought, its normally at least half full.
Anyway I pulled the dipstick out and dabbed it on a folded rag and had a sniff. It smelled like petrol to me. :(
The oil and filter was only changed <100-150 miles ago so the oil is more or less clear/yellow not Mini Slimy Black.
Now I have only just rebuilt that fuel pump but it is perfectly possible the 1975 NOS rebuild kit was no good.
But the level of fluid on the dipstick is pretty normal and wiping the dipstick and then taking another sample and placing it on clean paper towel doesn't show 2 distinct "rings" in the resultant oil-puddle (oil in the middle and petrol round the edge).
As a precaution I have hoiked the old rebuilt pump out and put a brand-new one in (losing loads of fuel in the process (oops!) ).
I took the old pump apart again and I cannot see any trace of fuel on the "dry/engine side" of the pump diaphragm (its as dry as a bone). So, have I just spooked myself into doing a lot of unnecessary work?

In the rework for the new pump I have removed the inline filter as it felt far too flimsy and the hose clamps had collapsed one of the 6mm plastic in/out pipes on it anyway(maybe why it was struggling to fill).
I don't want to chuck away 4.85L of perfectly good new oil and a filter if it isn't necessary, but that is cheaper than a new engine.
The trouble is that petrol and oil are miscible and once mixed you cannot unmix them. That's why my question.. is there a reliable test to determine if there is fuel in the oil. My BIL suggested getting a sample out of the sump and trying to ignite it as a puddle. Oil won't, petrol will?

Best answers and advice to this old duffer.....please. :)
I think you may have been smelling petrol that was leaking out of the filter. It is also surprising how little petrol seems to flow through one at tick over or even higher revs, at standstill.
 
OK, I pulled some oil out of the sump and deposited it in a glass ashtray. I tried to set light to it with the lighter I use for my wood-burner. No "flame-flash" and it did not burn. I assume this means there is not a lot of petrol/no-petrol in the oil then. :D
Panic over. :)
 
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