petrol in engine oil?

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Tom mccrea
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Location: Carrickfergus N.Ireland

petrol in engine oil?

Post by Tom mccrea »

right the saga continues. I did an oil changed last week and it was latte coloured. On closer inspection (with my nose) its it smells like petrol. I then conducted a little experiment in my garage mixing oil with petrol and got similar results colourwise to the old oil i drained. I did think head gasket, could this have been a low ball sending me the wrong direction?

I spoke to my dad who had a kwacker years ago, he had a coil problem which meant the bike only fired on 2 of 4 cylinders and the oil went a similar way. Has anyone else heard of this happening?
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Miles
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Re: petrol in engine oil?

Post by Miles »

The only way I can image oil and petrol mixing is via the piston rings
ie. Worn rings or bores. But I would image that if the bike is
running then the fuel would get burnt off, at least enough to not
notice it in the oil. Try doing a compression test and see what comes
up
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RedexRobB
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Re: petrol in engine oil?

Post by RedexRobB »

fuel can also get through from the airbox, the breather is right at the top of the box and feed down to the back of the crank case, probably not the problem but worth looking at.

As miles said give it a compression test, i think even with good compression fuel can still seep past the rings if its sat in the bores, so you might want to look at the carbs if the compression is good.
Tom mccrea
zxr400 oc member
zxr400 oc member
Posts: 89
Joined: Fri Jul 16, 2010 3:14 pm
My Bike: H1zxr400&cbr600fw
Location: Carrickfergus N.Ireland

Re: petrol in engine oil?

Post by Tom mccrea »

Well after cargo very kindly gave over an hour of his time we are 90% sure it was petrol in the oil, he had a listen and recons she's fine so next thing is putting back together and maybe get the track hired for a couple of hours. Need to sort brakes and tyres first though. Once I find out if she's running well enough I can set out to make it look a bit better.
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