The backpack blowers can't be beat for homeowner usage if you have heavy leaf cleanup. The only thing the contractors may have that most HO's will not is wheel mounted blowers and pull behind shredding machines hooked up to box trucks for carrying and dumping.

Congrats on the 600. If my 420 dies, I'll probably get one of those.

I purchased a BR600 two years ago to replace my BR420C (Which I gave to my daughter, and still runs great). The BR600 has a lot more power. I use the STIHL Ultra synthetic 2 cycle oil to prevent carbon buildup in the 4-Mix engine. I did check the valve clearance at about 150 hrs as recommended, and found an adjustment was necessary. Outside of that, it starts easy, has lots of power, and runs great. Charles Ranheim

Run that puppy at WOT or you will have problems with carbon buildup and poor performance.The ultra synthetic is the best oil to run in the 4-mix engines, there are some reports of bottom end failures with other brands.

What do you mean by bottom end failures? Do you mean failures of other brand motors using Stihl Ultra?

I heard the valves of 4Mix engines are made of brass, it this true? That is a very critical part, at high speed, the valve slam back to the head everytime it close. Using anything short of steal seemed funny!!!

I meant failures of Stihl engines when other oils are used. The valves are not made of brass.

Thanks for clarifying. What are they made of? I kept hearing about that.

My dealer did explain that I should use Stihl HP Ultra full synthetic oil, and he also suggested I should use premium gasoline. He said gas pre-mixed with HP Ultra would be fine for all my other OPE as well, including my Stihl BG75 hand held blower and FS81 trimmer, and a 1977 vintage Jonsered 52E chain saw that still works perfectly!

I can't control where the leaves go at WOT, and I fear for my neighbors' ears, so I hope I don't encounter too many operating problems at lower throttle levels.

Even though I was using STIHL Ultra oil, I found what looked like too much carbon on the spark plug. I had been using 3oz of oil per gallon of premium gas. Under advice from others, including tech support, I went to 2.6oz per gallon of gas for a 50:1 mix, instead of 3.0oz for a 42.6:1 mix. My spark plug now stays much cleaner. I also checked the valve clearance for the 2nd time and found it needed vary little decrease in gap compared to the first time I checked it at about 150 hrs. So far, it still starts easily and runs great. There was still a lot of oil accumulation under the valve rocker cover with the 50:1 mix. I guess it proves using more oil than recommended is not a good thing. Charles Ranheim

I notice same thing with my Shindaiwa C4 blowers. When I open the valve cover, I do see a lot of oil. Seems like the oil settle out more in 4 cycle because it stay in the engine for one cycle before going into the combusion chamber. I am using Amsoil at 64:1 and found the muffler and the exhaust port cleaner than using Echo Power Blend, Shindaiwa One, Mobil 2T and Ultra and 50:1.

I also use Deep Creep to decarbon occationally and put Sea foam in the gas to keep my C4 clean.

I sometimes spray some Sea Foam in the spark plug hole while the engine is hot, then let it sit for an hour or two before starting it. I am afraid of mixing any kind of cleaners with the fuel, because it is drawn through the crankcase for lubrication first. I don't know what harm this might cause to the bearings or seals. This is only my thoughts. I have nothing to prove it causes harm. Charles Ranheim

I read a lot of people put SeaFoam into gas. It only 1oz for a gallon. Itself is oil base anyway. I hope it won't damage the engine. The instruction just said use with the oil mix, don't substitude 2 cycle oil with Sea Foam. So you have more oil in the mix using Sea Foam.

Deep Creep is Sea Foam in spray form, I use that to spray into the carb according to instruction for decarboning. Try that, should be easier than spray Sea Foam yourself.

I always use the "Deep Creep" version of "Sea Foam." I have never seen a bottle of just plain Sea Foam. Again, I do not spray it in the carburetor of my BR600 because it goes right into the crankcase first, before going into the cylinder where the carbon would be. I do, however, spray it in the carburetors of my regular 4 cycle engines. When I do use use it to de-coke my BR600, I spray it in the spark hole of a hot engine, pull it over a few times, then wait an hour or two before start-up. Once the smoke clears, it runs great.
Charles Ranheim

I bought Sea Foam in Pepboy. This is more like gas treatment. I put 1oz in one gallon of gas regularly to keep the engines clean. I read a lot of people do that to 2 and 4 stroke and love it.

I did Deep Creep on my Shindaiwa C4 blower!!! It survive, I hope it didn't do any damage. I have not done it on my 2 cycles yet because the exhaust port and the muffler are all very clean, no cleaning even required. THe C4 is always the dirty one. I use Amsoil, seems like the C4 is not as dirty as using other ones that I experiment with.