The best way to break in a motorcycle engine has certainly been the topic of more than one heated discussion. We’ve heard all different methods, each stating that it is “the best” or “the only” way to break in a new engine. There’s the break-it-in-like-you’re going-to ride-it method, which is really just “beat the hell out of it, and just don’t worry about it.” Then there are those who baby the engine so much, they damage it by lugging it and not circulating enough oil. It doesn’t matter whether it is a 93-cubic inch S&S-Series engine or a 124-cubic inch V Twin Series engine, we have figured out what offers the best results down the line. Follow these steps for your new or freshly rebuilt engine, or a brand new bike:
1) Initial start-up: Run the engine approximately one minute at 1,250 to 1,750 rpm. DO NOT crack throttle or subject it to any loads during this period, as head gaskets are susceptible to failure at this time. During this time check to see that your oil pressure is normal and that oil is returning to the oil tank.
2) Shut off the engine, and thoroughly check for any leaks. Let the engine cool to the touch.
3) After the engine has cooled, start it again and allow the motor to build some heat. The engine should be run no longer than three to four minutes. When the cylinders become warm/hot to the touch (approximately 150 degrees) shut the motor down and let it cool to room temperature.
4) Repeat this procedure three or four times. Each successive time it should take slightly longer to warm up, and you can increase the temp slightly each time (+10 degrees). You can be more liberal each time with the rpm, gently varying the engine speed continuously from idle up to 2,500 rpm in the final cycle. Don’t be too concerned with final carb settings at this time cause idle speed and mixture cannot be correctly set until the motor reaches full operating temperature. The motor should not reach that temperature during these cycles. Do not allow engine temperature to become excessive. After the motor has cooled to room temperature for the Final time, you are ready to start the 1000-mile engine break in process.
5) The first fifty miles are absolutely the most critical for new rings and piston break-in. Any unnecessary engine damage is most likely to, occur during this period, Do your best to keep the heat down, and don’t exceed 2,500 rpm. Avoid lugging the motor and riding in heavy traffic. Change your engine oil and filter at fifty miles.
6) The next 500 miles should be spent running the engine no faster than 3,500 rpm or sixty mph. Avoid Continuous steady speeds, and do not lug the engine. Vary engine rpm. We recommend changing the oil again at 500 miles.
7) For the balance of the first 1,000 miles, the motor can be run in a normal but conservative manner. You can be more liberal with the rpm range, and the motorcycle can be operated at normal highway speeds. Avoid overheating or putting any hard strain one engine-no drag racing, dyno runs, excessive speed, trailer towing or sidecar operation.
8) After 1,000 miles, verify carburetor jetting and, adjustment. Change the engine oil, and then change your oil every 2,500 miles thereafter. Now for your next question-”Can I break in the engine using synthetic oil?” Based on testing done at S & S, they proven that you can break in an engine with synthetic oil, and everything will seat and mate up just fine. If you choose to use standard oil for break in, that is acceptable as well. Just be sure that its motorcycle oil and not automobile oil. After the first fifty miles, we do recommend the use of Mobil 1 20-50 V-Twin synthetic oil for long term protection.
