Do It Yourself Section My Garage Section Parts Look Up

Over 1,000,000 Orders Shipped Since 1997!

Do It Yourself - Outdoor Power Equipment Repair & Maintenance

Oil Changes

Oil Changes Posted in Small Engines

READ YOUR OWNER'S MANUAL.

Check out our selection of repair manuals, parts,and tools.

Oil Is Oil, or Is It?

The two main purposes of oil are lubrication and cooling. Oil transfers internal engine heat to the cylinder block and ultimately to outside air. If the oil level is low, less oil is trying to do the same amount of work. Oil temperatures will typically be higher. Higher oil temperatures tend to shorten oil life. As oil deteriorates, it can no longer perform its primary function - separating moving metal components. Once metal contacts metal, engine damage occurs. If the damage occurs to the cylinder walls or rings, there is no longer an effective seal between the two. This results in "blow-by" where oil passes the rings and is consumed in the combustion chamber. Oil, like gasoline, contains a hydrocarbon base. It will not burn efficiently in the combustion chamber and will increase hydrocarbon emissions.

The scenario for old, dirty oil is similar. Oil oxidizes (deteriorates) when exposed to air and heat. As it deteriorates, it looses it's viscosity. The viscosity of a fluid relates to its internal friction and results in a resistance to flow. It is this property that allows it to separate components. Loss of viscosity, or separation, eventually will allow metal to metal contact, engine damage, subsequent blow-by and an increase in emissions.

A Maintenance Schedule

Poor or improper maintenance can easily increase engine emission outputs of Hydrocarbons. If for no other reason, proper maintenance is critical to protect a frequently costly investment.

The key to any maintenance schedule is to recognize that regular, proper maintenance is the best insurance against premature failure and wear. Any maintenance schedule is an average determined through years of experience by a manufacturer. Engines with more frequent maintenance last longer as well as maintain reduced emissions levels.

Oil Change Schedule

  • Change Oil after the first 5 hours of operation. Remove the drain plug and drain oil while engine is warm. Replace the drain plug. Remove the dipstick and refill with new oil of the recommended grade (see table below). Start and run engine at idle for 30 seconds. Stop engine. Wait 30 seconds and re-check oil level. If required bring level to FULL mark on dipstick
  • Change oil every 25 hours.
  • Check oil level regularly, Check every 5 hours of operation and daily before starting.

Use a high quality detergent oil classified "For Service SF, SE, SD, SC OR BETTER"

  • Below 20° use 5W-20 or 5W-30
  • Between 0° and 100° 10W-30 is acceptable. However most engines will use oil more rapidly with 10W-30 above 40° than straight 30W. So check the oil more often.
  • Above 40° use 30W
  • Some engines, like the Kohler Commands, should use 10W-30 oil year around. These engines have valve lifters that require 10W-30 to operate correctly.
  • Only use 10W-40 as a last restart. Some engines have failed in as little as 10 hrs. operation under adverse conditions when using 10W-40.


Jack's Safety Tips: Before servicing or repairing any power equipment, disconnect the spark plug and battery cables. Remember to wear appropriate safety glasses and gloves to protect against harmful chemicals and debris. View our Disclaimer.