Can't argu with you on any of that. The early BR 4 strokers did have a major exhaust valve problem, no question about it. They cooked a exhaust valve way way faster than they should have. The problem was met head on and corrected with a new valve made of a different material. They also has some valve guide problems, impeller problems and some even had rocker arm problems. I think the backplate on these blowers were beefed up too, not because they were defective but because of how the landscapers kept breaking them by hanging them by the handle flying down the road. When everything was address and corrected the blower became what it is now, one helluva blower.
No way was Stihl going to can these blowers because of how clean they ran. They are going to be on the market for a long long time. I think the EPA rates the BR550 the cleanest running blower made today. The investment to build these EPA approved blowers well outweighed the problems that had to be corrected.
I was told Peter Stihl came to Va Beach and was confronted with the valve problems. His reply was simple, fix it, the 4-mix is here to stay. Everything was fixed and its been one helluva blower ever since. Best part is any blower within that range of early ones in the beginning are covered under warranty no matter how old it is now. Some people bought those early blowers and rarely use them. If 6-10 years from now such a blower within serial number range of those first ones lose a valve or have any valve train problem at all Stihl will warranty it.
The synthetic oil did correct some problems. No question it sure did enhance the life of not only 4 mix motors but regular 2 cycle motors as well by not leaving so much carbon behind. In a motor with valves carbon build up is more critical than a motor without valves. The valves get carbon build up and then won't seat correctly resulting in lost compression and power. I was told this carbon build up on the valve also retained alot more heat than a clean valve. So yes the synthetic oil is a huge plus for any motor with valves and a big plus for 2 cycle as well.
Since these blowers have had all the early issues addressed guess what, the failure rate of Stihl's 2 cycle blowers are higher today than the failure rate of these 4 mix blowers. Thats a quite a feat for Stihl considering there were alot of problems that had to be corrected and were and they did it fast.
Power wise on a sled test the big blowers from other manufactures didn't fare any better than the BR600. I can't say which is the most powerful of the big blowers from all makers but I'm very sure which one is the most comfortable to use. The weight factor and how Stihl keeps most of the weight very close to the backplate is a huge plus over the other big blowers out there.
Far as sales go at our last meeting we were told Stihl is closing in fast on being the No.1 selling brand of blowers in the world. Stihl blower sales with these 4-mix blowers jump 30% the first year they came out and they were the ones that had the issues. I assume all those issues ran some away but from what we were told at that meeting those days are history. Stihl blower sales now are better than ever. I know Echo has always been a good selling blower. They have had issues cleaning them up though. Teaming with Shindiawa to address that problem puts them behind Stihl for the time being. Time will tell who's going to win the blower war, I'm betting Stihl,