I just had to check in this turning into an oil thread and all....LOL.
From reading all these opinions I would say that there is a case to argue for most all of them at one time or another. Depending on your point of view you could bring up examples of each.
I have seen LOTS of new engines broken in by various schedules and with various oils and lubricants. LOTS of them. 150 in one study alone that were torn completely down and thoroughly analyzed. Never saw any data or trend indicating an immediate oil change would help the life of the engine.
Couple of things to consider. Most all manufacturers use some sort of ZDP rich assembly lube on critical wear surfaces. This small volume of assembly lube will spike the factory oil fill with extra ZDP. So, while there is usually no "special break-in oil" the oil in the engine originally likely does have more ZDP in it to protect against wear during the break-in period. Getting rid of it too soon will take away some of that protection, although it probably doesn't really matter as the main break-in of mating surfaces occurs very rapidly in the first few minutes of operation. Anything after that is pretty minor, generally.
If properly fitted, bearings and the crank surface do not "break-in". I have seen brand spanking new engines run immediately at full throttle for 2 hours at peak RPM/smoking hot oil/smoking hot coolant and the bearings look absolutely like brand new. You couldn't tell that they had been run in most all cases. The crank never touches the bearing if the clearances are correct and the oil film is sufficient.
This is important because any debris in the oil is meaningless as long as it is smaller than the oil film thickness. 35 micron particles floating around in the oil will cause absolutely no harm if the oil film thickness is 50 microns. There is no pressure to imbed the particles into the bearings and no clearance small enough to trap them. This is important to realize because every engine would fail immediately if the "debris" in the oil were to be trapped in the bearings. So a lot of what you might "see" in the form of metallic looking debris in the oil really is pretty harmless since it is so small.
Remember, oil from the sump is unfiltered. That oil will go thru the filter before it goes back to the bearings and get any particles large enough to cause a problem removed. The rest won'd hurt anything. That is also why the most important time for a filter is during the first few moments of the engines life by a wide wide margin. Makes it sort of funny to hear people obcessing over which filter is best when they are putting it on the engine long after the "best" filter is needed. That is why the OEM filter is usually the "best" filter as the OEM knows it had better be the best to get the engine thru the first few moments of breakin.
Almost all, if not all, the breakin debris comes from the piston rings burnishing the cylinder walls. Nothing to speak of comes from the bearings and crank. Maybe a tiny bit from the piston skirts but piston skirts, like bearings, ride on an oil film and rarely if ever show ANY sign of contact at all for thousands of miles. Microscopic aluminum debris might show from the piston ring lands as the most important breakin feature is the burnishing of the ring sides to the sides of the ring lands in the piston. No much material removed here but there is polishing and mating of the sides of the rings and the sides of the ring lands during breakin.
Some debris may be generated during breakin from the gear box of a bike. I suspect that most of what anyone sees in motorcycle breakin oil is the particles from the clutch plates burnishing the metal clutch plates in the clutch assembly and knocking any "burrs" off the splines in the clutch drums, outer and inner. That can definitely create shiny metal debris.
BTW, most all surfaces mentioned here that might create debris are aluminum and aluminum debris, especially microscopic 30 micron particles, are pretty much benign anyway. Since the bearings are aluminum, anyway, any imbedment of aluminum particles causes little or now harm. Imbedment of cast iron or steel particles can certainly mar the crank and erode the crank surface if the oil film gets thin enough....but there isn't much of that being generated in a bike engine if any at all.
Oils, assembly lubes, machined surface finishes, tolerances, etc. from all manufacturing operations are dramatically improved since the old-wives tales of breakin requirements were generated by our dads and grand-dads in the 40's and 50's and such. Most of those old stories just do not fly in todays engines.
Per an earlier comment.....spark plugs can and easily do last 100,000 miles or far longer these days. Dual platinum electrodes and unleaded fuel has made the spark plug a virutal life time part. I have seen them go that far and far many many times. Not that the occsional one might not be damaged from installation, fouling due to another problem or something, but the vast vast majority will run forever without being removed.
Similarily for oils , long change intervals and oil life monitors. No manufacturer actually practices "planned obselescence" and no one recommends extended drain intervals or break in oil changes that might harm the engine. To think otherwise is rediculous. The fact is that more damage is done to the vehicle fleet in general from oil changes, putting the wrong oil in, upselling the "customer" with un-necessary additives and treatments, etc. then would ever occur due to longer change intervals. Every time someone goes under the hood of the average customers car a risk is taken. The only way to prevent or minimize this risk is to keep the hood closed and keep the car out of the dealer/oil change depot. That minimizes exposure to upselling additives, the wrong lubricants, poor service procedures, etc. An often hidden and un-discussed reason for longer change intervals.
Is anyone going to hurt their FJR by an early and repeated oil change...?? No. Is is necessary? No. If there was a particular problem with breakin or necessity for unusual service I suspect that would have been addressed by the OEM with a design change, additional assembly lube, etc. It is more a "feel good" sort of thing but it isn't likely to do any harm except wear out the threads of the oil drain plug.
Rad does make a good point about loosening and retightening the oil drain plug early on, in my opinion. If the plug is overtorqued by Yamaha for some reason or the threads damaged, it would theoretically be good to break it loose and retighten (not so tight) before any microscopic galvanic corrosion occurs at the steel/aluminum thread interface that could cause additional damage. I have never seen any data to back this up, by the way, and I have looked at a lot of aluminum pans with steel plugs on car engines. It just makes common sense, though.
I ran my engine to 2000 miles and changed the oil and filter. Oil looked perfectly fine. No sign of debris or metallics other than a trace in the oil that settled at the bottom of the pan. That might be machining debris from assembly that is very benign as it just lies in the bottom of the pan anyway. Cut the filter open. Trace of debris in the filter. Nothing unusual at all. Certainly no "metallic oil" or huge amount of debris. Must have gotten another "Team Yamaha" engine...LOL.
Ever look at your oil from the Briggs and Stratton on your lawn mower. Just full of metallics. Yet the engine runs fine with no oil filter yet. Tribute to the power of the oil film thickness and the fact that the oil film thickness is thicker than any of the particles you see. So, they do absolutely nothing.
It is amazing at the emotion involved with oil discussions. I find oil interesting because of what I have learned about it and how the facts differ so significantly from what people believe and how fervent they are in their beliefs. I think this is mostly because changing the oil and "selecting" the correct oil is one of the few things left to an owner of an engine so many take that responsibility to the religious level. Just ask an amsoil true believer....LOL.
Anyone that thinks they can leave spark plugs in a car for 100,000 miles and be 100% sure they will come out is living in fantasy land. I have heard from plenty of experts strongly advising against this.
These "experts" wouldn't be the morons from "Two Guys Garage" would they...???