Help-Stihl BR600 blower

terrifictimbersllc · January 31, 2016, 02:34:37 PM

UPDATE : It might be fixed. Have to use it a few more times to be sure. Jump down to post 56 to see how: https://forestryforum.com/board/index.php/topic,88417.0/all.html#lastPost

9 year old Stihl BR600 blower, lightly used, will only accelerate about 1/4 of the way before sputtering and shaking.

Starts and idles great. Not improved if I remove the air filter. New spark plug is sooty. New carburetor, pickup body, spark plug, clear exhaust screen, good fuel, throttle opens all the way, valves adjusted, ignition-flywheel clearance good, primes fine, problem remains with air filter removed.

Any suggestions greatly appreciated, I don't want to throw out this blower for something simple.

------------------------------------------------------------------------below is where this all began-------------

Recently, my Stihl BR600 backpack blower has been running erratically for the first time in 10 years. Usually starts on 1-2 pulls as always. But at times it runs great at full throttle, then others like it has trouble getting gas, sputtering at a medium low speed. Seemed like a time for replacing the pickup body and all the fuel lines, and if that doesn't do it, do a carburetor rebuild.

Yesterday I couldn't get it to pull over, pull on the cord was like it seized up. So I started to look at it just now.

First thing I did was take out the spark plug. Now it pulls fine, BUT.....fuel comes squirting out of the spark plug hole on each pull. The cylinder movement is obviously blocked by liquid when the plug is in.

What's going on? Any help appreciated. Wanted to use it tomorrow.

dougand3 · January 31, 2016, 02:47:45 PM

Sounds like severe flooding...may be carb needle is stuck open. Needs carb cleaning and rebuild, at a minimum. Maybe a new carb.

terrifictimbersllc · January 31, 2016, 02:51:18 PM

Quote from: dougand3 on January 31, 2016, 02:47:45 PM
Sounds like severe flooding...may be carb needle is stuck open. Needs carb cleaning and rebuild, at a minimum. Maybe a new carb.

Thanks. I should take the carb apart right now and blow and clean it wherever I can see if that helps.

Any other comments appreciated.

terrifictimbersllc · January 31, 2016, 04:22:00 PM

Cleaned carb out & reassembled, same problem, very hard to pull but easy with plug removed and a lot of liquid fuel in there. Could there be something blocked on the exhaust/muffler end ?

dougand3 · January 31, 2016, 04:32:29 PM

Possible that muffler screen is so blocked that it's a closed system with no exit. But it'd have to be REAL BLOCKED and it would have run like crap with no power before this. Surely worth checking. Did you check that needle is seating properly? I'd look at getting a new carb - AM ones are going to be $20 or less.

terrifictimbersllc · January 31, 2016, 05:16:27 PM

Muffler screen dirty but not blocked at all. Does pull easier with muffler off but muffler doesn't seem blocked at all. Lots of gas in muffler still.

The needle valve is in top of the carb, beneath a pivot mechanism, right? How would I know if it is seated or not? With all the messing around in last 2 hrs the carb now needs rebuilding for sure.

I am not seeing a model number on the carb like on my chainsaws like walbro xyz etc. Says Stihl Chiina, C10 and a couple other numbers. Any idea how to i.d. this carb to get a rebuild kit?

Very grateful for your help on Sunday afternoon. thanks

dougand3 · January 31, 2016, 06:02:25 PM

Your carb sounds like an open pipe...trouble. The needle has a lever with spring under it. Press lever - needle opens. Lever returns up - needle seats. Either your needle tip is trashed or seat is trashed. 10 years is a long time on a carb. I wouldn't spend money on a carb kit. I'd get a new carb = Zama C1Q S183 or AM replacement. Search web for best deal.

Al_Smith · January 31, 2016, 07:19:38 PM

Well some people have problems rebuilding carbs and some don't .I'm among the later group myself . ;)

It could be something as simple as a fuel pump check valve not seating which after 10 years would be no surprise.

If you are going to attempt to rebuild it being a Zama you have to make certain all numbers match or it won't work .There must be a dozen kits for the C1Q carb .---or just bite the bullet and get a new carb .It would be a shame to shelve a BR 600 just for lack of a carb, nice blower.

terrifictimbersllc · January 31, 2016, 08:42:28 PM

I searched for the zama carb c1Q s100a couldn't find it, think you have to get it at the stihl dealer guessing $50-60.
I found the zama rb-166 rebuild kit only $14 with shipping no harm trying that, in the meantime I'll see what the stihl deal is. if that's reasonable I'll just order it and skip the rebuild.

There were a bunch of aftermarket zama carb lookalikes for about $20-25 would rather get the original if i'm getting a carb.

I think it was the needle valve, when I gently pressed it in deeper, it went a bit further than the spring would push it. there was fuel at the bottom of the seat maybe that was giving resistance i don't know, I don't really understand the plumbing in there. then the spring popped out on the floor . but i'll get a new one in the kit.

thanks again for your help ill let you know what happens

ZeroJunk · January 31, 2016, 10:02:31 PM

Quotebut i'll get a new one in the kit.

I don't think they include the spring anymore. May want to double check before you spend $14 and can't find the original. They are a perpetual motion machine you know.

terrifictimbersllc · February 01, 2016, 06:08:42 AM

Some are called gasket and seal kits, don't have spring & needle valve. Others like the Zama RB-166 do.
http://www.amazon.com/Zama-RB-166-Repair-Stihl-BR500/dp/B0074LQKFC

Al_Smith · February 01, 2016, 07:41:30 PM

I took the liberty of looking up that carb on flea bay .They range from about 20 bucks up .If you want an official "Stihl" in the original package they go as high as $76 .Probably cheaper at the dealer as flea bay sellers often try to raise the ante.

Some "purists" might think just because it says Stihl it's better .I'll refrain from opining on that just because I'm a nice guy . ;D

ZeroJunk · February 01, 2016, 08:02:17 PM

I would bet they come off the same assembly line myself since Zama is made in China .

Texas-Jim · February 01, 2016, 08:08:11 PM

The C1Q isnt the model it should have a second set of numbers like S100 , that S number is one that determines the kit you need. If its a S183/184/185 a new carb from Stihl is 49 bucks. The other series are no longer offered as complete carbs. And for the record there is no comparison between an off brand part and a Stihl [art. In 7 years I have had one bad Stihl replacement carb, I have an entire box of the ebay carbs that are bad out of the box. You get what you pay for.

Texas-Jim · February 01, 2016, 08:10:16 PM

Zama is actually owned by Stihl but Zama makes carbs per the customer specs, they are not created equal. But it is cool place to visit if ever get chance.

joe_indi · February 02, 2016, 12:22:43 AM

The BR600 has a 4Mix engine. It is a four stroke engine and so the valve clearances have to be checked once in a way. In your case it would be that the valves need to be adjusted. You will need to take it to a shop for this. But if you want to attempt a DIY, this video clip that I made some time ago might help. But in the video the engine I have used is a FS130 brushcutter. The flywheels are different and the timing marks are different. But I mention it in the comments. https://youtu.be/waPf0oDAVOg

ZeroJunk · February 02, 2016, 12:48:01 AM

Molds are expensive as the dickens. Stihl destined carbs may have a more extensive QC. But, I won't believe they have two different lines running them until somebody shows me a picture.

terrifictimbersllc · February 02, 2016, 04:34:58 AM

Quote from: Al_Smith on February 01, 2016, 07:41:30 PM
I took the liberty of looking up that carb on flea bay .They range from about 20 bucks up .If you want an official "Stihl" in the original package they go as high as $76 .Probably cheaper at the dealer as flea bay sellers often try to raise the ante.

Some "purists" might think just because it says Stihl it's better .I'll refrain from opining on that just because I'm a nice guy . ;D

Thanks, after I saw what was going on with knockoffs for now I was trying to stick with a Zama carb, it doesn't have to say Stihl. But the Zama 100 looks like it is a Stihl only carb.

terrifictimbersllc · February 02, 2016, 04:36:48 AM

Quote from: Texas-Jim on February 01, 2016, 08:08:11 PM
The C1Q isnt the model it should have a second set of numbers like S100 , that S number is one that determines the kit you need. If its a S183/184/185 a new carb from Stihl is 49 bucks. The other series are no longer offered as complete carbs. And for the record there is no comparison between an off brand part and a Stihl [art. In 7 years I have had one bad Stihl replacement carb, I have an entire box of the ebay carbs that are bad out of the box. You get what you pay for.

It says S100 and 609A at one place, and at another there is 183.

terrifictimbersllc · February 02, 2016, 04:38:34 AM

Quote from: joe_indi on February 02, 2016, 12:22:43 AM
The BR600 has a 4Mix engine. It is a four stroke engine and so the valve clearances have to be checked once in a way. In your case it would be that the valves need to be adjusted. You will need to take it to a shop for this. But if you want to attempt a DIY, this video clip that I made some time ago might help. But in the video the engine I have used is a FS130 brushcutter. The flywheels are different and the timing marks are different. But I mention it in the comments. https://youtu.be/waPf0oDAVOg

Mine is 2006 model, will it still be 4Mix? Didn't see that anywhere. Is 4Mix still a 50:1 mix fuel?

Al_Smith · February 02, 2016, 05:23:08 AM

4 mix, really ? I was under the impression perhaps erroneously it was a larger version of the Br 400 of which I own one .

Good info.
l"ll know to avoid one if it ever presents itself .That's all I would need is a 2 cycle with valves .Good grief!

ZeroJunk · February 02, 2016, 10:37:20 AM

It's more a four cycle that uses mix rather than an oil pan. They have a lot of torque and run well. But, when they go south it is not a matter of just sticking another piston in there. I think they addressed some early issues with valves and they seem to be reliable. They increase the warranty for using HP Ultra as carbon build up and valve failure is reduced.That is about all the lawn and land scape guys use around here.

beenthere · February 02, 2016, 11:28:21 AM

joe_indi
Great tutorial on the video.
tks

sawguy21 · February 02, 2016, 12:22:43 PM

Quote from: Al_Smith on February 02, 2016, 05:23:08 AM
4 mix, really ? I was under the impression perhaps erroneously it was a larger version of the Br 400 of which I own one .

Good info.
l"ll know to avoid one if it ever presents itself .That's all I would need is a 2 cycle with valves .Good grief!

Al, I could not agree more but these engines are the way of the future. Conventional 2 strokes are too 'dirty' from an emissions stand point, they are also too noisy. Many urban areas have restrictive bylaws limiting decibel levels, Stihl has a BR500 which is a low noise version but performance suffers. Like you, I am hanging onto my older equipment as long as possible.

terrifictimbersllc · February 16, 2016, 06:30:48 AM

UPDATE.

I rebuilt the Zama/Stihl S100A carburetor using the recommended Zama RB-166 rebuild kit which included spring & metering valve part. There was a clear path through the L inlet needle screw hole so I didn't take out the Welch plug.

Unfortunately now the primer bulb only sucks up air through the top of the carb (metering valve side), instead of fuel. This air is coming in through the main bore of the carburetor, I know because when I block it off with my thumb and finger it will then suck mostly gas with some air up from the fuel tank. Aterwards the main bore is wet with gas.

I don't have a clear picture in mind of the carburetor internals but it seems to me there must be a check valve inside the carb that is not working right or else the primer would work to prime the carb not just suck up air.

Any suggestions? I would like to fix it if I can it's the principle of the thing. But I can just get another carburetor over at the hardware store/Stihl dealer.