Read the owners manual before you ride and follow the guide.

Throw the owners manual away and just floor the sucker! Just don't keep the RPM at any one speed for an extended period of time. Vary the RPM.

Most of the new cars or bikes today don't need the motors to be broken in. As stated above DON'T REDLINE the engine. Drive as you normally would. If it's mostly freeway miles vary the speeds as much as possible. Maintaining speeds at constant does not allow the engine to "seat" everything as would variations of acceleration and decelerating would. When break in oil was used it was normally changed at around 500 miles, but todays engines don't use it anymore. Change oil whenever the manufacturer recommends and the engine should last till the car starts rusting apart. I just got rid of my F150 with about a quarter mill of miles on it. The engine was great but the salt from winter driving was eating the frame away. Same goes for all my bikes.

The three replies so far are pretty close to the mark. It was very important once to run engines in with care because in the distant past bearings, for example, were hand scrapped and often quite tight.

These days there is not a lot that needs to be run in. Piston rings are a main area of concern and the word there seems to be to give them a few hits of max acceleration so that the gas pressure really seats them home - not too long though (more than a few seconds each time) as else the temperature might build up in a poorly seating ring. There is a web site I cannot recall where a motorcycle pro demonstrates in some detail, with photos, the advantages of "max for short periods" as comapred to the "go softly alwys" methods of running in.

It is generally agreed I think that as a second stage part of the process that engine revs and loads should be varied and not too hard for too long until (say) 1000 km are under the belt.

On a lighter note, I remember watching the BMW people run up each new car on a dyno as part of the final check prior to leaving the factory. Those in the crowd who were old school were horrified at the relatively hard time each vehicle was given for the short period involved.

Very important—allow sufficient warm up to operating temperature prior to driving new equipment. Find long stretch of open road, run a little above lugging in third gear for about twenty miles, bring in and drop the oil and filter then do it the way you want to.

http://www.mototuneusa.com/break_in_secrets.htm

This is the process we have always used on our fresh race bike engines. Very successful. Same theory applies to all modern 4 stroke engines. Jess, Dunedin, New Zealand

Thanks to all for replying.

In our region, most of the people drive 70cc bikes. would the same rule (Top Speeds and Engine Break-In Periods) apply to those bikes as compare with racing bikes?

Hi Every car or bike's new engine undergoes some hours of running period to lap the engine to prevent further engine seizure and failure before its final fitting onto a vehicle. But it's preferable to cross limits after a vehicle gets its first servicing done, but not restricted.

I used to replace engines using rebored blocks from a little old man I knew and he maintained that once the timing was done correctly etc., the best way was to get in the car with full water bottles, a few sandwiches and an empty bladder! Start the engine and drive 200 miles at between 30 and 50 MPH.....not stopping as much as possible just driving with a light throttle and early gear changing.....

The engines that were so treated exhibited a higher BHP and a much reduced oil usuage, sometimes as good as no oil used between changes (going at worse from full to the low mark on the stick).....

That was mostly on A and B series motors from the Austin Morris cars as well as MGAs, MGBs, Sprites etc...

I probably replaced 50 or 60 motors over a 3 year period.....though I never counted......

On new cars I still drive a few 100 miles at a reduced speed and find that my oil consumption is still minimal......