Several OEM's have been doing it for years. JD with Kawasaki, and you won't find a parts diagram for a Kaw on JD on any USA parts lookup system for Kaw. Craftsman did it for several years also. Dealers could look up parts for engines used on Craftsman mowers, but warranty was a Sears exclusive item. Husqvarna is doing it now with Rato, and LCT engines. Generac has used Rato and Loncin engines and branded them their own. MTD has their powermore engine which are also rebranded.
Then basically these engine manufactures takes no responsibility for defective products. At least most of these engines I can find parts for these engine without having to pay a premium to places like JD and Sears. But of course these engine manufactures are giving the equipment OEM a big fat discount on the engines. JD buys the Kawasaki engines in bulk which is why most the labeled model/spec numbers end an "-R". This stand for rack of engines. If you happen to find one with a "-S" that just mean it was a single engine purchase.
These companies have been using a legal loophole for years. This loophole should be plugged but these companies are deep in the politicians pockets.
I had to warranty engines myself that I sold new as I not a dealer myself. Heck I can't even get new defective replacement parts warrantied. Example is Briggs where even I buy the parts through a Briggs parts distributor where they will not honor the warranty. I supposed to get the local dealer to honor the warranty when I have the invoice where I brought them from the distributor. None the local dealers will honor the warranty. And Kohler has the same policy of not honoring parts warranty. I had absorb the cost of two ignition a few years ago the Kohler told me was under warranty but none of local dealers would honor it. It was the same with Briggs when I got two defective $100 fuel solenoids. This probably because they can't get Briggs or Kohler to honor the warranties either. Having absorb these cost is hard for a small shop like mine.
As a result none of those local dealers get referrals from me anymore nor do I buy parts from them now.
The local JD dealer did me dirty too. I started out with a 10% discount of all parts. First they took away the Stihl discount, then they sneakily took away the discount on all of the other parts to. Now they add a shipping charge on nearly everything I order. They now give my shop a quoted price on parts and then jack it up when the parts came in. Otherwords they quote me a price for parts and then would not honor it. I have basically quit buying JD parts locally as they can't even honor their word.
This why I most of the JD parts now out of Indiana from a dealer that gives me the 10% discount and has fair shipping charges. Matter of fact I got an order going in today for aftermarket belts for Z830, Z925A, Z950R, and 737 ZTR. All this means is that I am only 10% above local dealer on the parts except for my senior citizen customers which receives a 10% discount on the parts.
As for the Stihl parts I found a local dealer that is giving my shop the 10% discount and rarely charges a shipping charge as long as I am willing to let him place the orders on his normal orders. It is a win win for him as he makes a profit on the parts and don't to spend time repairing the equipment. It is a win for me as I get the labor plus I make 10% on the parts. And it is a win usually for the customer as they get a quicker turn around most times, except lately with parts being constantly b/o.
Come people just keeping buying Chinese manufactured equipment and they will put the thumbscrews to you later.
Right now I got in the shop a very nice 22 yr old Yazoo ZTR base on the Husqvarna ZTH6125A that I can't even get any of the parts for now as Husqvarna flat quit supporting the ZTH6125A. It is now running on borrowed time. I just made a make do repair using a couple beer cans as I needed an idler arm and bushing which I can't get now.