Tecumseh VLV Technician's Handbook page 52

Cause
Oil level too high.
Oil filler cap loose or gasket damaged causing
spillage.
Engine speed too fast.
Gaskets damaged or gasket surfaces nicked
causing oil to leak out.
Breather tube not connected to air cleaner.
Using 10W30 oil under high load/high temperature
conditions.
Breather mechanism damaged or dirty causing
leakage.
Drain hole in breather box clogged causing oil to
spill out of breather.
Oil passages obstructed.
Piston oil control ring return holes clogged.
Piston rings and grooves worn excessively.
Cylinder wall worn or glazed, allowing oil to
bypass rings into combustion chamber.
Piston fit undersized.
Valve guides worn excessively thus passing oil
into combustion chamber.
Crankcase breather plugged.
Seal outside seat in cylinder or side cover is
damaged, allowing oil to seep around outer
edge of seal.
Old seal hardened and worn.
Crankshaft seal contact surface is worn undersize
causing seal to leak.
Crankshaft bearing under seal is worn excessively,
causing crankshaft to wobble in oil seal.
13-3
Table 1. 4-Cycle Engine Troubleshooting Chart (Continued)
Engine Uses Excessive Amount of Oil
Oil Seal Leaks
Remedy and Reference
To check level turn dipstick cap tightly into receptacle for
accurate level reading.
Replace ring gasket under cap and tighten tube securely.
Using tachometer adjust engine RPM to spec.
Clean and smooth gasket surfaces. Always use new
gaskets.
Reconnect tube.
Replace with SAE 30 oil.
Replace breather assembly.
Clean hole with wire to allow oil to return to crankcase.
Clean out all oil passages.
Remove oil control ring and clean return holes.
Reinstall new rings and check land clearance and correct
as necessary.
Bore cylinder for oversized piston & rings.
Measure and replace as necessary.
Ream valve guide oversize and install 1/32'' oversize valve
and new valve seal if equipped.
Clean or replace breather.
Visually check seal receptacle for nicks and damage.
Replace P.T.O. cylinder cover, or small cylinder cover on
the magneto end if necessary.
Replace seal.
Check crankshaft size and replace if worn excessively.
Check crankshaft bearings for wear and replace if
necessary.
695578