Running a new ATV engine can be a nail-biting experience. It’s important to get it correct. The break-in period will affect how the engine performs throughout its life.
To break in a new ATV, follow your manufacturer’s break-in recommendations. A typical new or rebuilt engine break-in procedure is as follows:
1 Use regular engine oil for the break-in procedure
2 Check fluid levels
3 Warm engine
4 Check for leaks
5 Run engine up to 75% throttle in 2 and 3 gear for 30 minutes
6 Change oil and filter
7 Repeat 5 & 6, and the engine is run-in
In this post, you’ll learn how I break in a new engine, and I’ll explain why I do it this way.
Getting a new set of wheels is an exciting time. These toys are expensive. You want to treat them right and have them for many trouble-free years.
When breaking in a new ATV, it’s the engine we’re concerned with. Most other components don’t need a break-in period.
I’ve been lucky enough to own a couple of new ATVs and a ton of used ones. I’ve rebuilt lots of engines, and in this guide, you’ll see how I break them in.
When engines are built, the cylinder is honed or crosshatched. That’s a system of polishing, if you like, the cylinder wall surface.
Crosshatching the bore creates an abrasive surface, and you’d think that counterproductive, but crosshatching is needed to help shape the new piston rings to the exact shape of the cylinder wall.
The better the cylinder and ring surfaces pair, the better she’ll perform over her lifetime. Your engine will be noticeable more:
- Fuel efficient
The break-in starts with the oil. Synthetic and semi-synthetic oil is excellent, but that’s a problem when breaking in a new motor. We want the rings and crosshatched bore to make good contact. Without contact, the bedding won’t happen.
Synthetic oil is too slippy for break-in. If your engine has synthetic oil in from the factory, change it, run with regular petroleum-based oil, just for the break-in procedure.
Pre Flight Checks
Check the fluids, allow the engine to idle for a few minutes to warm up. Take this time to check for any leaks or loose components. When the engines warm, we’ll start the break-in procedure immediately.
Run Engine at 75%
You’ll need somewhere you won’t be impeded. It isn’t practical to run a break-in session where there’s traffic or pedestrians etc. A quiet country road is ideal.
Run the bike at 75% throttle in 2 and 3 gear, varying the time spent at 75%. Allow the engine decelerate, again varying the time spent decelerating. Run this cycle for 30 minutes, keeping an eye on the temperature.
If the bike gets too hot, use good sense, run it in a higher gear and back off the throttle.
The break-in period doesn’t last long on a new engine. For most, the window is a few hours of running. After that, the opportunity is lost. The rings and cylinder are pretty much as mated as they’ll ever be.
Do you think 75% throttle is too much? Yea, I can see why you’d think that. I run at 75% because I want the piston rings pushed hard against the cylinder wall for as long as possible during the break-in window.
The higher rpm creates more ring cylinder wall pressure and, therefore, better pairing.
Change Oil & Filter
After 30 minutes run time, drop the oil and filter and replace again with non-synthetic petroleum-based oil. I’ll change the oil because at this stage risk of contaminants in the oil is high. The break-in sessions will cause fine metal particles to circulate the oil system.
Rinse & Repeat
Check all fluids and allow engine idle to operating temperature once again. Repeat the break-in drive cycle for another 30 minutes, as before.
After two-thirty-minute sessions, your engine is broken in. I changed the oil and filter again, but this time use the recommended grade oil. You may be semi or fully synthetic. I changed the oil again after about 8 hours of running time and from then as per your manual.
If your new ATV is CVT belt-driven, break-in is minimal. Most manufacturers will ask that you refrain from running at full throttle until the belt beds in. Overheating the belt can cause glazing and transmission slip.
That’s it, congratulations, and enjoy many years of trouble-free ownership.
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