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oil out breather

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It must be coming from the (Rubber?) pipe. On most engines these go back to the carb. If blowing oil it is putting raw oil inside the cylinder, It may mess up spark plugs. :D

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Check out your valves,i had this problem and it turned out to be carbon build up keeping the exhaust valve open a bit,the engine vaccuum was pulling oil up and out the breather,worth a look.

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Hi, We have seen this problem a lot. Briggs came out with a square o-ring for the dipstick. This was to reduce the possibility of a crankcase leak. Any leak in the crankcase will cause this problem to occur. The most common cause we see is a leaking head gasket. The engine will run fine and then when it gets under load when mowing, it will puff a cloud of smoke. Compression checks normal, cylinder leakdown test is normal, crankcase vacuum is normal. Problem is a head gasket that is leaking. It only leaks when the engine is under a load. The head gasket is leaking into the oil return passage or the push rod area. The gasket doesn't leak unless the engine is under load, then the increased cumbustion chamber pressures seep into one of these areas. This reduces the crankcase vacuum and lets the oil blow out the breather into the air cleaner, soaking the filter with oil and choking the engine, washing the cylinder and adding gasoline to the crankcase. Then it smokes all of the time. I would just about bet you have a leaking head gasket. I would expect that the cylinder head will be warped in excess of .004 in. If this was an engine in warranty and the head and or block was warped, we would replace either or both. If it is an older engine, we resurface the head on a flat plate to fix it. It has been our experience that once they are warped and trued, they tend to stay straight. Be sure to check the block and head for warpage or a new gasket will repeat the performance. When you look at the gasket it will not look blown, but if you look carefully you will be able to see where it has seeped. I'll bet we have seen this in 50 28cu in engines. It is the most common internal failure we see in the Vangard twins. It is less common in the newer ones with the Graphoil head gaskets. It is kind of ironic that one of the tech writers at Briggs called me today about another matter, and we got into a discussion about this very problem and the writing of a new failure analysis manual and a new electrical manual for the advanced schools. The fact is that it is almost impossible to diagnose with standard testing is one case where a problem flies in the face of the standard process, test, test and evaluate. This is one place the new Tecumseh engines excel. They have 5 head bolts instead of 4, one in the center of the push rod area. Hope that in the future Briggs engineers can see the advantage of that. Remember that if your head is more than a couple of thousanths from flat it needs fixed or repaired. Good luck, my 2 cents worth and its free, value accordingly. Al Eden

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