143.049001 should be the proper model #. When i look at the Sears manual, it shows 20 oz of SAE 5w30. The oil is right , but the oil amount has to be off. The medium frame Tecumsehs were 26 oz if i remember correctly.

ok, thanks

Try this:
The dip-stick has graduated lines on it. The top most one is where the oil level should be when filling the crank-case. Thats the large, box-shaped casting, below the finned part!
Pour in some oil, then take out the dip-stick, wipe it clean, re-insert it, and pull it out again and look at it. If the oil is at the top line/ full line, thats enough oil. Do not add any more oil! If not at the full line, sparingly add some oil, checking after every couple ounces, until the oil level reaches the full mark/ line on the dip-stick. You should wipe the oil off the dip-stick after every time you check the oil level, re-insert it, pull it out, and that will show you the true reading.
now, what was the saying about the thirsty horse???