STIHL BG85C blower - carb removal

Discussion in 'Mechanic and Repair' started by Roger, Nov 10, 2011.

  1. jtsnipe

    jtsnipe LawnSite Member
    Messages: 199

    First take compressed air and clean that thing so you can see what you have.My dealer had both the carb kit ($17.00) and the carb ($27.00) in stock.Guess which one I bought.
  2. Roger

    Roger LawnSite Fanatic
    Messages: 5,943

    Thanks for the comments and feedback.

    MowerMedic, I now agree with the handle disassembly to get the throttle wire out. That seems to be the only way.

    I have another source of blower, so the pressure to get this one back in service has been eased. This means I can take it apart, get the numbers, get the parts, and put it back together. I hate taking the steel-to-plastic screws out multiple times (those in the handle). The risk of plastic failure is high. But, now that I can take more time, I need to disassemble and reassemble only one time.

    Yes, I made some inquiries about carbs and G & D kits. I got a quote about the same that was mentioned here. So, putting on a new one seems like the way to go.

    And, yes, it does need to be cleaned up. When I took it apart, I was hoping to quickly get the carb number, and put it back together, hence the lack of cleaning at that time. I didn't think I would even need to get this far.

    Thanks again for the input, and responses.
  3. Saw Dr

    Saw Dr LawnSite Member
    Messages: 9

    I would check the fuel lines before you order anything. You may get away with a new line and a cleaning of the fuel screen in the carb.
  4. Roger

    Roger LawnSite Fanatic
    Messages: 5,943

    Update: I had some time late this afternoon to take the project to the next step. This time, I took off the starter housing, and one half of the handle. This exposed the channel for the throttle wire, and allowed me to pull off the throttle trigger. It is hinged on a post, and captured between the two halves of the handle.

    After getting the trigger and wire out, I was easily able to remove the Z-connection from the carb. Then the two hoses to the carb were taken off. The carb pulled right off the posts.

    I believe I was right -- the posts are captured pieces with a hook on the bottom end. They are "loose" when I took the carb off, both in the transverse direction as well as the rotational direction.

    Here are several pics, from the handle being split, the throttle trigger and wire being removed, and then the carb coming off.

    After the carb came off, and I got it cleaned up, I was able to determine that it is a ZAMA C1Q-S68B. I've shown the places where the C1Q is stamped (deep down into the inset), and where the series number is stamped (albeit faint).

    I have located a supplier and ordered a new carb (rather than a GND kit). BTW, after the last pic, the next stop was at the air compressor for some cleanup.

    During my Google search, one entry came up near the top of the list:

    This is a thread more than three years old. But, the carb is identified in post #11. While on the goose-chase to find the information, it was right under my nose!!! I thought I had done a search, but apparently didn't look closely enough.

    Perhaps all this information will help the next BG85 blower user needing to make a repair.







  5. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Messages: 2,249


    Although, I've never had a Stihl down that far, my guess is that the two carb mounting screws are simply hex headed capscrews retained in hex recesses in the isoblock.
  6. Saw Dr

    Saw Dr LawnSite Member
    Messages: 9

    They are. That is why it is important to make sure they are indexed properly before you start tightening down the carb/filter assy nuts. I have seen more than one of these intakes cracked. Same on all of the FS/FC/HL/HT 75/80/85 series.
  7. blutch

    blutch LawnSite Member
    from OKC, OK
    Messages: 1

    I know this is a very old thread, but I'm having trouble with this particular blower. It hasn't started or run well in awhile, so I replaced the carb with a brand new one today. It still won't start. Just won't turn over. Any ideas on getting it going?

  8. Patriot Services

    Patriot Services LawnSite Fanatic
    Messages: 14,506

    Start with the basics. Fuel, air, spark. Then compression. Check for spark and add a spray of cleaner. You should get at least a pop. If not, check kill switch and coil.
    Posted via Mobile Device
  9. Roger

    Roger LawnSite Fanatic
    Messages: 5,943

    Do you mean by "won't turn over," it is locked and the crankshaft will not turn? Or, can you pull the cord, and it turns, but won't fire?

    If the latter, is there any hint of combustion? Any small sign of "catching?" Or, it is just turning, but "dead?"

    As suggested, what about spark? Do you have an inline tester to determine if a pulse is getting to the spark plug? If not, then perhaps you have a bad ignition module. How old is the blower? Lots of use, or just an hour each week?

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