New engines are built to tight tolerances, and the first hours of operation are when parts finish wearing in against each other. Most manufacturers give break-in instructions, and many call for an early first oil change to remove the fine wear particles that are normal in a new engine. The owner’s manual is the authority here. Follow it over anything general, including this page.
General break-in habits
- Read the manual first, including the break-in section and the first service interval.
- Check the oil before the first start. Many machines ship without oil in the crankcase, or with a low fill.
- Vary the load and speed. Many makers advise avoiding long periods at constant speed or full load at first.
- Watch for leaks and loose hardware after the first few uses.
- Make the first oil change at the interval the manual gives, which is often much shorter than later intervals.
About break-in oil
AMSOIL offers a dedicated break-in oil aimed at freshly built or rebuilt engines. For new factory equipment, follow the manufacturer’s instructions on which oil to use during break-in.
New-machine checklist
- Register the product and keep the receipt for warranty.
- Fill or check every fluid before first start: oil, fuel, bar oil or premix as applicable.
- Use fresh fuel, mixed at the correct ratio for 2-stroke equipment.
- Follow the break-in steps in the manual for the first hours.
- Recheck chain tension, belts and bolts after the first use.
- Log hours from day one so the first service happens on time.
- Plan the first oil change and have the right oil and filter ready.
Frequently asked questions
Should I use synthetic oil in a brand-new engine?
Follow the manufacturer. Some recommend a specific oil during break-in; others allow synthetic from the start.
When is the first oil change on a new mower?
Many small-engine manuals call for an early first change, often within the first several hours. Check yours.
Does a new chainsaw need break-in?
Many makers recommend running the first few tanks without long periods at full throttle. Follow the manual and keep the chain sharp and oiled.
AMSOIL products for this job
- AMSOIL SAE 30 Break-In Oil. AMSOIL says: “Quickly seats piston rings”; “Increased zinc and phosphorus protect against wear”.
- AMSOIL 10W-30 100% Synthetic Small-Engine Oil. AMSOIL says: “Protects up to 200 hours”; “Helps extend engine life”.
- AMSOIL SABER Professional 100% Synthetic 2-Stroke Oil. AMSOIL says: “Stabilizes fuel during storage”; “Use in all handheld two-stroke equipment or other applications that specify JASO FD, ISO-L-EGD or API TC”.
Product wording above is quoted or summarized from amsoil.com. Read each product’s label and data sheet for directions.
Use AMSOIL’s official lookup guide to see what is listed for your vehicle or equipment, then order online whenever it suits you.