Oil in carb ?

[thedawnpatrol]

I probably over filled my engine oil very slightly the other day, however this caused oil to enter the top of the carb, as there is a pipe that comes off the valve cover and upto the air intake on the top of the carb. Now she struggles to idle, so it's off to Halfords tomorrow to get a tin of carb cleaner!

 

Is this something that can happen easily? Could I put some sort of filter in that pipe, why do I even need it ?

 

Bloody annoying as she was running beautifully before hand.

 

 

Cheers

 

 

Jules

[Starfire]

Is this on an older vehicle? Generally, this kind of arrangement is seen in vehicles from the 70's onwards and is an attempt to reduce emissions by recirculating the gunk and fumes that would come out of the crank case breather into the inlet stream of the vehicle for further combustion. Vehicles prior to this generally just had a small filter or a tube that would just spill any overflow onto the road. I guess an exception, and someting that is in place on my Saracen, is for vehicles with relatively sealed engines for fording; the crank case has to breathe, but the fumes have to go somewhere, the inlet being a fairly simple solution.

 

In order to prevent this happening again, you need what is called an oil catch can, and these are commonly used in motorsports or performance cars. You can also make one yourself without much trouble (I've seen some functional but unattractive ones made from some hose and a coke bottle). There are also about a billion different Chinese made ones available on eBay.

 

Cheers,

Terry

[FourFox]

It's probably just a small quantity of oil gone into the engine via the carb and inlet manifold and will not have done any serious harm. Try cleaning the plugs. This may be necessary more than once as all the oil in the conbustion chambers will have to be burned off. A good long run at full working temperature is best.

 

Incidently it can be very harmful to some engines (especially diesels) to overfill with oil. This can cause frothing of the oil when the rotating parts of the engine thrash around in contact with the high sump oil level. The crankshaft breather then can transfer a great quantity of oil froth (and sometimes just liquid oil) into the inlet manifold and hence into the combustion chambers.

 

On 2 occasions I have had to sort out diesel engines that have 'run away' by consuming their own lubricating oil in this way.

 

Jon

[thedawnpatrol]

Thanks Jon & Terry

 

it's my 1942 Humber, so yes, i'll clean the plugs and the carb tonight, runs fine at speed, just won't idle happily seams to 'hunt' so i hope just an easy fix.

 

cheers

 

Jules