It is usually above the float in the little bowl at the bottom of the carb.
10w40 will work fine!
.030"
10w40 motor oil will work fine!
My 5 horsepower Tecumseh on my John Deere snowblower takes : ( 20 ounces / 600 ml )
one quart. Use the oil dipstick!!
My book for my John Deere snowblower , which has a 5 horsepower Tecumseh engine , shows to use the Champion RJ17LM spark plug
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Sounds like u have carburetor problems!
According to my owners manuel the spark plug gap is 30
Check internet for book form 69590, this is techumsehs carb identification, troubleshoot, and service book. Very helpfull!
whats the float setting on a bst34 carbator