Small Engines (Lawn Mowers, etc.): Oil Ring replacement, dipstick tube, engine crankcase

Question
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Followup To
Question -
I have a Sears Garden Tractor with a B&S 19.5 HP engine that is blowing oil and running a bit rough. It's about ten years old and has seen light to moderate use. Both plugs appear to be oil fouled. Originally, I thought the problem may have been bad gas, so I did the carb rebuild with the Sears kit and replaced the fuel filter, but it ran the same. Does this sound like a ring problem or perhaps a valve guide problem? Is this something worth fixing myself?


Thanks for your help.
Answer -
Has the oil been changed regularly?  If not, try changing the oil to see if it helps the problem.

It has been many years since we have replaced any rings.  Generally we would do a full rebuild if the rings were that wore.

Have you checked the valve breather.  If the breather is clogged the engine crankcase maynot be holding vacuum causing the oil to get past the rings.

Do you have a manometer or vacumm gauge?  Also, if you have a dipstick with o-rings on it you will want to check them for sealing.

Let me know about the tools.
Eric

The oil is changed once in the beginning of the season and doesn't look too bad - not black. I do not have a pressure gauge, manometer or vacumm gauge but can borrow one or more. The dip-stick has a screw-on cap.

Where is the valve breather located?

Mike

Answer
The valve/crankcase breather is usually located under the air filter housing depenind on your model. One way to find it is to follow the tube from the air filter housing to the breather.

If you have o-rings on either the dipstick tube or on the top of the stick where the threads are I would replace them both.  Leaky o-rings on the dipstick has been a problem on Briggs engines that causes oil consumption/burning.

Let me know if the o-rings and an oil change helps.
Eric