Intermittent white smoke from BSA F12 Sloper engine

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Mr. E
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Intermittent white smoke from BSA F12 Sloper engine

Having installed the felt washer on top of the gauze in the Amal air intake chamber, and in accordance with the instructions for the Marquis 18 I topped up the oil to the top of the felt washer in the intake chamber, the engine has been running well but intermittently been blowing white smoke. 

I take it that I have over filled the oil in the air intake - the Norton Villiers F12 instructions state that you should wet the felt and gauge with oil (having washed them in petrol) and shake the excess oil before installing them into the intake chamber.  This contradicts the Ransomes instructions which tell you to fill oil in the intake chamber to the top of the felt washer...

Which is right?

wristpin
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Before worrying too much

Before worrying too much about the exact oil level it may be a good idea to check that it is the air cleaner oil that is causing your problem. Remove the gauze disc, felt disc and washer and then clean out all the oil and run it with just the lid on. If that eliminates the smoking it suggests that you are on the right track and should, perhaps put a bit less oil in the filter bowl.

Just bear in mind that when running the engine draws some oil into the gauze element in the lid to act as a dust trap so until that oil has migrated back into the bowl you will not have a true level. **

If running without air cleaner oil does not cure your problem it may pay to have a look at the crankcase breather valve on the front of the block. The moving part of the valve is a small nylon mushroom shaped insert and they do wear. The seating face of the breather body also wears. The inserts are still available and it is possible to “ square up” the seating face of the body if you can find someone with a suitable end mill cutter, but try a new insert first.

In the days when F12s were regular visitors to our workshop, it was not unknown to find the inserts missing.

** EDIT

I've just dug out an F12 Maintenance Manual and it says - 

"The oil-wetted air filter should be serviced at regular intervals by removing the top cover, taking out the gauze and felt pad and washing all parts with clean petrol. Allow them to dry and dip the element and felt pad in clean engine oil. Drain off surplus oil and reassemble".

NOWHERE DOES IT SAY ANYTHING ABOUT ADDING ANY EXTRA OIL

https://www.dropbox.com/s/z68ejb7mhrwec9v/Villiers%20F12%20Sloper%20engi...

Mr. E
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Wise words Wristpin!

Wise words Wristpin!

However the Ransomes Marquis Mark 4a Operator's Instructions state "Air Cleaner - lever off the top cover and remove the felt washer, inner wire gauze and felt pad and soak these parts in engine oil.  Replace in the same order as removed and pour in sufficient engine oil to just cover the felt washer"

I agree with you that the Norton Villiers F12 Handbook makes more sense as to oil level.  Having said that my 1955 Series One Land-Rover has an oil filled air cleaner in which the oil bath is filled to approximately 1/3 full, and oil is not sucked into the combustion chamber.

 

Having run the engine with no smoke not having poured additional oil in to cover the felt washer, then put the oil in to cover the felt washer and found it intermittently blowing white smoke out I am going to soak up the additional oil and see what happens.

Mark

Mr. E
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I have also checked the

I have also checked the breather and all appears well there, with the plastic inward piece present...

Mark

Mr. E
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Sorted!  Having removed the

Sorted!  Having removed the felt, gauze and felt washer from the indeed air chamber to the Amal carburetter I removed the excess oil from the bottom of the bowl and also from the base of the cap's gauze mesh filter.  Fired her up and no white smoke!  Thanks Angus, for the tip.  So the instructions for the Marquis 18 Mk 4 are incorrect...

Mark