Below the correct procedure to break-in your engine .
1- Initial start up. Run engine approximately one minute at 1250-1750 rpm. DO NOT crack throttle or subject to any loads during this period as head gaskets are susceptible to failure at this time. During this time, check to see that oil pressure is normal, that oil is returning the oil tank, and that no leaks exist.
2. Shut off engine and thoroughly check for any leaks or other problems. Let engine cool to the touch.
3.. After engine has cooled, start up again and allow the motor to build some heat. Engine should be run no longer than three to four minutes. When the cylinders become warm/ hot to the touch (approximately 150°) shut the motor down and let it cool to room temp. Follow the same cautions as for the initial start-up, and continue to watch for problems.
4. Repeat this procedure 3 or 4 times. Each successive time it should take slightly longer to warm up and you can increase the temp slightly each time (+10°). You can be more liberal each time with the rpm, gently vary rpm continuously from idle up to 2500 rpm in the final cycle. Don’t be too concerned with final carb settings at this time because 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 50 miles are most critical for new rings and piston break-in. Engine damage is most likely to occur during this period. Keep heat down by not exceeding 2500 rpm. Avoid lugging the motor, riding in hot weather or in traffic. Vary the engine speed. Do not lug the engine. We recommend changing the oil at 50 miles.
6. The next 500 miles should be spent running engine no faster than 3500 rpm or 60 mph. Avoid continuous steady speeds, and do not lug the engine. Vary engine rpm. We recommend changing the oil a gain at 500 miles. CAUTION: Lugging or running engine prematurely at sustained high rpm may result in damage to pistons and other engine components. S&S voids it’s guarantee if engine is not broken in properly.
7. For the balance of the first 1000 miles the motor can be run in a normal but conservative manner. You can be more liberal with the rpm range and motorcycle can be operated at normal highway speeds. Avoid overheating or putting any hard strain on the engine: no drag racing, dyno runs, excessive speed, trailer towing or sidecar operation.
8. After 1000 miles, verify carburetor jetting and adjustment. Change the engine oil. Motorcycle can now be operated normally.
S&S engines are designed for high performance and as such are not as tolerant of inadequate break-in as stock or lower performance engines. Correct breakin will assure longer engine life and will prevent unnecessary engine damage. Engine damage caused by improper break-in is not covered under the S&S warranty.
I’ve known this for years, glad people will get a better understanding on how to treat a motor early in its life.
What type of oil for break-in — Dino or Synthetic? I’ve heard it both ways. I personally have used Mobil 1 20w50 V-twin Synthetic oil for break-in on several high performance builds and never had a problem.
Hi:
The first part seems a bit strange,…
Do they not run the engines for several (10s) minutes before they leave factory ?
Does the dealer never start the engine ?
BR : Miha
Bruce from S&S here. Let me answer two questions at once.
Oil – Some folks like to break in with dinosaur oil, and switch to synthetic afterward. It makes sense since your going to change oil at 50 miles any way. Saves some bucks! We’ve done it both ways and it works either way.
The heat cycling does two things, it helps the head gaskets to seal and it also makes the valve springs last longer. Keep in mind that S&S engine have higher lift cams and pretty strong springs. It’s not as critical with a stocker.
We don’t actually run the engines at our factory, they are put on a special computerized machine similar to a spintron for end of line testing. During the end of line test they are spun up with an electric motor to about 3000 rpm with hot oil. Cylinder pressure, oil pressure and a number of other perameters are measured. There is no gasoline involved.
Whoever starts the engine for the first time, dealer or end user should follow this procedure. Needless to say that race engines don’t get pampered like this, but they aren’t expected to last a long time anyway.
Bruce is an ol’ grey beard who knows what he’s talkin’ about.
You tell ’em Bruce 😉
Nothing says fun like a new S&S motor coming to life the first time..and the ensuing fun sure to follow…
Great instructions for any interal combustion engine from 1 cylinder to V16’s
Thank you for the info ,,,