We all know what a wonderful feeling it is, to lay our hands on the first brand new bike. Many would have bought it after months of savings from their salary; others own it after months of praying and arguing with their parents. Any way, it’s an important part of our life now and we take every necessary care to make it more efficient and smooth.

But the user manual from the manufacturer hardly provides us with enough information to properly go through the running-in phase. Data like not to run the bike above 50KMPH for initial 500Km is all we get out of a user manual. A quick search over the internet will land you to use either Hard Break-in procedure or Run-in Procedure which are controversial and contrary to each other, so you end up in a dilemma of choosing between the right procedures. 

Why to Run-in/Break-in your Engine:

For a newly build engine, the parts come in contact with each other and wear out. The parts like cylinder wall, piston surface however may appear smooth, but when viewed under microscope the surface peaks and valleys can easily be seen on the hard metal surface , these peaks need to be flattened out so that the piston rings may seat properly against the wall of the engine,thus not allowing the engine oil to enter the combustion chamber.

Honda, KTM, Hero,Bajaj cylinder wall
Peaks & Valleys on a metal surface

 A proper Run-in/Break-in procedure makes sure that the cylinder walls wear uniformly which there by allows only a very thin layer of engine oil between the metal parts thin enough to lubricate but not allowing the metal surface to rub against each other.

Run-in Vs Break-In Process:

There are two popular ways to run-in your engine, first is to ride the bike slow , below certain RPM and keep on increasing the maximum speed limit with change of engine oil in every service . The other method is to hard run-in or Break-in where as you give short bursts of high RPM and keep on repeating the process of accelerating and slowing down.

With the first run-in process you do not need to change the engine oil at once, but can be done on specified servicing period, on the contrary with the hard run-in/Break run process it is recommended to change the engine oil immediately once you complete the process as the oil contains many small shredded metal parts.

How to Run-in/Break-in

One of the most critical parts of the engine building process is the break in !!
No matter how well an engine is assembled, it’s final power output is all up to you.
Running-in: The engine running-In process may vary from Manufacture to Manufacture depending upon at what RPM the engine produces maximum torque. The key to running-in method is to slowly increase the maximum speed limit of the bike with every oil change.

Honda, Continental GT, Hero, Bajaj Engine
Engine description

Run-in method:

Start the engine and let it run ideal for 5 min, and now for the initial 500 Kms do not take the bike for more than 50Kmph-60Kmph.Make sure you are riding the bike below 3500 RPM. Try to vary the speed from time to time. The engine must be allowed to cool off in covering long distances.

Now over 500Km to 3000Km you can increase the pace of the bike by 70-75Kmph with varying speed. Do not forget to allow the engine to cool. The RPM can now be increased to 6000.

Post 3000Km you can increase the speed further. The engine oil and air filter must be change on every service. The engine must be allowed to cool off from time to time to prevent the overheating of the engine during the running-in period.

Break-in method:

Start the engine and let the engine run ideal for 5 min, so that the engine oil can lubricate well the cylinder wall and the piston. The main thing is to load the engine by opening the throttle hard in 2nd, 3rd and 4th gear below the red line. The best method is to alternate between short bursts of hard acceleration and deceleration continue this for some 20km-30km keeping your RPM below the redline. It is recommended to change the engine oil once you complete 100Km of hard break-in. Also, make sure that you’re not being followed by another bike or car when you decelerate, most drivers won’t expect that you’ll suddenly slow down, and we don’t want anyone to get hit from behind.

A overheated piston
A overheated piston

The biggest problem with breaking-in your engine on the street you would not get enough space in traffic to accelerate and reaccelerate the machine properly. For the first 200 Kms, get out into the highways where you can vary the speed more.

Not too few rpm’s

Most manuals don’t tell you that, apart from avoiding too high rpm’s, you should also avoid too few.
Riding with too few rpm’s means that the engine would work too hard, in the same way as it is hard work when you ride a bicyle in a very high gear.
A guiding rule is: try to avoid running the engine below 2500RPM and keeping the RPM at optimum level in every gear. After the break-in period, you can keep the same rule (though you can dive under it from time to time).

Damaged cylinder wall
Damaged cylinder wall

Change oil

You will probably understand that it is very important to change the oil after the break-in period. It will contain small particles of metal residue , and you don’t want those between the piston rings and the cylinders!

Check the oil

Breaking in is, as we have seen, needed to reach the point where every metal part seats well onto the other parts. So, before the break-in period is over, it is possible that there is a bit of oil consumption.
So check the oil level from time to time!

Be Safe On The Street !

While using any of the above procedure watch your speed ! When you’re not used to the handling of a new vehicle, you should accelerate only on the highways, then slow down extra early for the turns. Remember that both hard acceleration and hard engine braking (deceleration) are equally important during the break in process.

Which Engine oil to be used during the Run-in Phase:

During the process of break-in the shredded metal chunks is captured by engine oil which can be later drain out.
Engine oil generally comes in two variant a) Mineral b)Synthetic
A Mineral engine oil provides less protection against the rubbing metal parts in the engine, thus allows the extra metal surface to wear out more quickly. Mineral Oil are more prone to loss of viscosity under extreme conditions that’s why further use of mineral oil after run-in period is not recommended.

Mineral and Synthetic Engine oil
Mineral and Synthetic Engine oil

Synthetic oils on the other hand can handle changes in temperature and engine load much better than mineral oils. They have added chemicals which reduce sludge formation. Synthetic oils have better low temperature viscosity and flows more easily in between moving parts in an engine. This means that it is less resistant, and can lead to enhancements in fuel efficiency and engine performance. Hence are recommended to be used after run-in.

Verdict:

There are two possible ways to run-in your engine and both are contrary to each other. Both works fine as long as the basic rules likes changing the oil on time and taking some precautions. Finally at the end of the day its your call how to handle your ride. Either you can go easy on your ride or can break-In hard.

about author-img author

I am bike enthusiast, keen to discuss everything and anything about bikes.. A software professional at work. In love with any machine with two wheels!

comments (6)

  • Reply

    May 23, 2014

    very good information. thanks for th knowledge. very helpful.

  • Reply

    May 22, 2014

    Hi Ashwin,
    I agree that the manufacturer based guidelines are risk free, but for sure they are not the best. The reason why manufacturer dnt suggest us to follow the hard break-in is because its risky if not done correct. just opening the full throttle for a duration of time may overheat a new engine very easily, damaging the engine beyond repair.

    On the postive side, a proper break-in means the engine runs smooth with better power and efficiency.

    • Reply

      November 30, 2015

      My brother performed Hard break in on his Bike P220 Dtsi. As a result Top compression ring worn and leaked oil in the combustion chamber.

  • Reply

    May 21, 2014

    It’s best just to stick with what the manufacturer specifies – both, for the the run-in and the engine oil. After all, it’s their engineers who designed the engine.

    Agreed, the synthetic oils retain their viscosity longer; but sticking to the mineral oil and sticking to the recommended change interval will cause you no problems.

    • Reply

      January 6, 2015

      Hard engine breaking is the best. Bike will last long.

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