Seems lots of people have opinions on this. I ain't arguin' with anyone, and I have my own opinions on it. But we all know about opinions, right? Anyway, having been riding and working on HD muttersickles for over 30 years, I figger I've at least made a down payment on some of my opinions. 'Course, you might still think they stink, but that's OK.

Here's what I've recently found concerning breaking in an engine with synthetic oil:

1) HD puts Syn 3 in the SE bikes, at least the 103" motors, primaries, & trannies I've seen at the 5 reasonably local HD shops. I made it a point to talk to the service manager or mechanics about any break in problems. They've seen none, except where somebody went out and hammered the motor immediately.

2) Here's what Mobil has to say about it:

Myth: You should break in your engine with conventional oil, then switch to a synthetic oil like Mobil 1.

Reality: You can start using Mobil 1 with SuperSyn Technology in new vehicles at any time, even in brand new vehicles. In fact, Mobil 1 with SuperSyn Technology is original equipment (it is installed at the factory) in:
Aston Martin
Bentley Amage and Bentley GT
Cadillac CTS, XLR, SRX and STS
Chevrolet Corvette
Dodge Viper
Mercedes-Benz AMG vehicles
Mercedes SLR
Mitsubishi EVO
Pontiac GTO
All Porsche vehicles

One of the myths that surrounds synthetic oils is that new engines require a break-in period with conventional oil. The fact is, current engine manufacturing technology does not require this break-in period. As indicated by the decisions of the engineers who design the high-performance cars listed above, Mobil 1 can be used starting the day you drive the car off the showroom floor.

3)Here's something from Quaker State:

Myth #6

Engines have to be “broken in” before using synthetic oil.
I need to break in my engine with non-detergent oil. If I use regular oil or synthetic oil in a new engine, my engine will take longer to break in.

Fact
It was common years ago for engine manufacturers to recommend non-detergent oils for engine break-in. This was when the pistons used cast-iron “square-faced” rings and the rings needed to wear some to “seat” into the engine. With today’s technology of oils and engine manufacturing, engine manufacturers no longer recommend the use of non-detergent oils for the break-in period. In fact, engines today are factory-filled with high quality API SL performance motor oil, which contains high levels of detergents and dispersant additives.

While it might be argued that the oil companies have a vested interest in selling their oils, to advise something that would cause them to be liable for literally millions in repairs would be foolhardy. If it affects their bottom line as that would, as well as the damage to their reputation, again screwing with their bottom line, they're not gonna do it.

I've seen nothing scientific that would cause me to believe breaking in a motor with synthetic oil will take longer, or damage the engine. I've heard and read plenty of anecdotal evidence that says the same thing. But I've also read of anecdotal evidence that says not to break in a motor with synthetics.

I've made my decisions to use synthetics in my bikes and cars after an initial period. I don't use them initially for one reason - they're expensive and I change the oil at 500, 1000, and 1500 miles. It has nothing to do with break in, I'm just a tightwad. After that I use 'em 'cause I believe they offer superior protection, and especially stand up to the heat of the area I live in.

You can use synthetics or not. You can use 'em to break in a motor or not. You can use 'em in your motor, tranny, primary, even in your deep fat fryer, if'n you want. It's your choice. Make it based upon whatever criteria you choose, and don't worry about what I, or anybody else, thinks. We're all nu

 

Poco,
Can't agree with you more. Now what I get a kick out of is everyone trying to run engine oil in the tranny. First of all the trany wasn't designed to run with oils like 20/50. They need the thicker oils and do not need to be running oils with detergents like in motor oil. I can't for the life of me understand why people think their bikes are running so much better, shifting better etc, etc, Blah, blah, blah with Syn3 or the equivelant there of in the tranny.
Here is my rule of break in and it has worked very well for me.
Go to the Motorman site and read up on what he says about break in. I did it on a couple of builds now and it works just fine. There is no excessive harsh treatment to the engine, it just builds the required amount of cylinder pressure to properly seat the rings in those first few critical miles.
People, read this and listen to me and others like me who have been playing this game for a while and wrenching and fixing yours and my mistakes for a good long time.
You run engine oil in the engine. You run tranny fluid in the tranny, Hey it's already semi synthetic anyway what more do you want and run primary fluid or a good grade of straight 30 weight oil in the primary. Some swear by the Redline products, others Mobil etc, etc. I don't care if you put Granny's oil in there as long as the oils you put in the respective holes are made for that application. That's all I can say about it.
Thanks for a good post Poco. SpiderJim.

 

After 35 plus years working on vehicles for a living and being involved in building high performance motors I agree with what you are saying. I did take it real easy on my 05 RK for the first 50 miles, as I could feel the motor was tight and we all know about air cooled engines and how hot they can get. After 500 miles I dumped all three and filled with Mobil One synthetics. 75/90 in the trans. Never could figure out why HD wants MOTOR OIL in a gear transmission that needs hypoid gear oil with the right shear additives ????????????????[:-]

 

Probably because it makes them more money and it's easier to stock than multi type oils, but it's still wrong to use that syn 3 in the trans.

 

>Never could figure out why HD wants MOTOR OIL in a gear transmission that needs hypoid gear oil with the right shear additives ????????????????

LOL.................maybe they are counting on numerous gearbox failures to service at about the time the bikes are out of warrenty.

 

Regarding using Syn3 in the gearbox, I was just at the dealer today picking up some oil and spoke with a few of the technicians there. They do not recommend using Syn3 in the gear box. They like the newer stuff Harley put out called Formula+ or the Mobil1 75/90. I havent read too much about the Formula+ on this site. Does anyone use it or know how well it works?

 

Pococj;
I agree with your comments about breaking in engines. There are a few schools of thought on that. Take your pick.

Now my opinion:

Break in your engine with the HD 20W-50 motorcycle engine oil that came in the bike. The reason is it won't be using it very long.

Drain it out at about 500 miles.

Change to Amsoil MCV 20W-50 in the engine, SVG 75W-90 Severe gear oil in the tranny, MCF 10W-40 in the chaincase. For the best oil filter go to http://formmailto.com/catalog and I will send you a free catalog and give you free shipping as well as tell you how to buy Amsoil products at dealer costs. Be sure to give me the model as well as the year of your bike.

Of course I am am Amsoil dealer.

I can show you why Amsoil is much better than Mobil 1 or Syn3..

NC Brew

 

I think I will take you up on that offer NC Brew. Are you in N. Carolina? I am away right now but will be back in NC in a few months. I would love to get a hookup on some quality oil. I am taking delivery of a new bike when I get home and will be going through the whole break-in process. PM or e-mail me if we can do business.

 

You are right.

I just did my first oil change on my first Harley 06 U/Classic and I used Mobile 1 SuperSyn 15W50 oil.

 

I don't know... I'm not disagreeing with you guys or saying that anyone is wrong. I don't know, and that's the problem. I will say this - Harley Davidson has a lot at stake when they tell you to break in your engine using a certain method, or when they tell you what type of oil to put in the tranny. They've got warranties to honor, the huge reputation that their business is built upon, and possible lawsuits to defend themselves from.... Now, I am not saying their word is always good, just that they've got smarter guys than me working for them. They've got engineers who actually designed the motors and trannies, and they tested and studied these things to no end. I don't know who Motorman is, nor do I know if his methods work.. but I do know of several HDs that have run beautifully for 100k miles and were broken in the way HD recommends. Same with the tranny oil. For that reason, I am going by the book. The HD book.