How To Break In Your Motorcycle Engine
Whether you have purchased a new bike or just completed an engine rebuild, many experts recommend breaking in a motorcycle engine. New components generate a high degree of friction as they have not adapted to one another. Gradually breaking in the engine controls the initial amount of friction as the shape of the components melds over time to create a smoothly running whole. On the other hand, getting on the road without taking the time to complete this process instantly subjects the new parts to a lot of stress, which in the long run makes them less efficient.
In particular, measured amounts of heat over a period of time are necessary to get all the components to fit perfectly. Skipping this process is bad for the cylinders and other internal components which could wear out quicker and make your engine less efficient, the parts wear prematurely, or worse lead to the parts failing or worse of all, catastrophic failure.
There are various methods of breaking in an engine; the effective ones tend to be fairly similar. While some feel more confident handing off this task to a professional, it is also possible to do it yourself if you are generally comfortable with motorcycle mechanics. Professionals will usually use a dyno to cycle the engine as needed. You probably do not have a dyno in your garage, but the following basic methods tend to work just as well.
The first step you want to take once you are sure the rebuilding process is complete and correct is to turn on the engine and let it idle for about ten minutes before turning it back off. Once the engine cools down, inspect the engine and see if there are any leaks or loose fasteners. If you notice anything that needs adjusting, do so and then repeat this first step again. This will ensure your motorcycle engine is ready for the next step, which involves actually taking your bike for a short ride.
Your first ride out of the garage should last for only about 10 minutes. Keep the RPMs low, but do vary them lightly. Back in the garage, let your bike cool down then check the engine again. Repeat the process three or four times. Each time, make the ride a little longer and gradually increase the RPMs. Keep checking the engine after it cools down following each ride.
If your first set of short rides goes well and your checks do not reveal any issues, you can try going for a longer casual ride. At this stage, you still don't want to pin the throttle, lug the engine, or go too long at a high RPM. During this initial period, you should also continue to vary the RPMs as you continue the breaking-in process.
When can you consider your engine broken in? Usually, completing the first 1,000 miles is a reliable benchmark. Until you arrive at it, keep checking to make sure the bolts stay tight and there are no leaks.
As a new engine adjusts, small metal shavings can come off the parts as they adapt to one another. Left to themselves, they can end up circulating around the engine and damaging it or clogging your oil filter. Make sure to change your motorcycle oil and oil filter frequently during the break-in period. Many professionals advise an oil and filter change at 100, 300 and 800 miles. Take a look at the filter. While it is normal to find some metal flakes, larger parts or amounts can mean problems. In addition to checking and changing filters, taking the time to slowly build up to higher speeds reduces the stress on the components and thus the amount of shavings.
If you bought a new dirt bike or rebuilt your dirt bike engine you can follow similar procedures, however since your bike most likely doesn't have an odometer you can base the break in procedure and oil change intervals on engine run time and gas tanks you've burned through. The first start up let the engine idle for about 10 minutes to get warm then shut it down. Then restart and ride the bike for about 15-20 minutes but don't rev too high, lug the engine, try climbing steep terrain or run the engine at the same revs for a long period of time--a gentle cruise over a beginner track works well. Don't give the bike more than half throttle. Then let the bike cool and repeat but ride for about 30-40 minutes and this time you can give it more than half but don't go over over 3/4 throttle. Let the bike cool and then go for another 30-40 minute ride and slowly increase the throttle amount. Once you get through your first tank of gas the bike should be fairly broken in and can be ridden normally. After your first tank of gas change out the oil and filter. Refer to your dirt bike owner's manual, as it may have a more specific or different break in procedure.
Whether you follow the above outline or a similar method, it is important to keep in mind the basic principles behind the break-in process. Chief among these is avoiding putting too much stress on your engine in a too short amount of time. During the break-in period, professionals recommend:
- Shifting up a gear rather than increasing engine speed
- Increase engine speed to the rev limit gradually and for short periods of time
- Keep your throttle at three quarters or less
- Avoid abrupt stops, starts and speed shifts
Be sure to also check your bike's manual for breaking-in recommendations and advice. If you did your own rebuild, you may want to check in with professionals to figure out the best approach. Following an optimal break-in routine can save you a lot of hassle and expense, as it will cut down on repairs, help your engine last longer and reduce gas and oil costs.
Whether you are looking for high-quality parts, expert advice or motorcycle service and repairs, the professionals at Chaparral Motorsports can help. Call us at 1-800-841-2690 to learn more about how we can help you get the ride you want.