Stihl BR420C very hard to start

Discussion in 'Lawn Mowing' started by habers, Oct 27, 2006.

  1. habers

    habers LawnSite Member
    Posts: 3

    I recently got a bunch of tools from my father one of them being a Stihl BR 420C Magnum blower. It looks very lightly used. Problem is that it is a beast to start. Takes me about 100 or so pulls to get her going. Once I hear it starting to fire (about 90 pulls into it) it doesn’t take too much longer but getting there absolutely wears me out.

    Could I be doing something wrong?

    My steps are, put the throttle half way, turn the switch to "on". Turn the choke on and pull and pull. About 25 pull into it I usually give up with the choke being on and turn it off and pull more and usually bounce between the two ‘til it finally starts. She wont even start to fire until about 90 or so pulls. Once it is running it runs great!

    Are these things suppose to be this hard to start. I have the Stihl chainsaw, hedge trimmer and weed eater and they start right up!

    Thanks for listening!

    Jon
     
  2. Runner

    Runner LawnSite Fanatic
    Posts: 13,496

    I think it's the throttle thing that may be messing you up. It should be starting without any throttle. Full choke, (if it hs a primer, prime it a few times until you feel the bulb full), pull it a few times until you feel it start to fire over. unchoke it, and pull a few times more. If you lose the "fire" of cranking over, re-choke. Stihls are really tempermental at starting, anyway. It sounds like it DEFinitely needs to be readjusted (carb). Once you get it fired up, redo the adjusatments according to proper procedure, and especially concentrate on you low end. THIS has everything to do with your starting. Also, dump your old gas and make sure you have fresher mix in it.
     
  3. Precision Lawns

    Precision Lawns LawnSite Senior Member
    Posts: 283

    dido: not throttle, full choke. once it turns over, unchoke (could add throttle).
    it should start up like your trimmers. I have all stihl equip also.
    definately get new gas mix if you havn't already.
    You may pull off the muffler and check for carbon build up, also.
     
  4. Richard Martin

    Richard Martin LawnSite Fanatic
    Posts: 14,700

    If the above advice doesn't work try this:

    1: Clean/replace the air filter.
    2: Replace the spark plug.
    3: No throttle
    4: Full choke
    5: Pull it 3 times
    6: Move the choke to halfway between full choke and off choke.
    7: Pull it no more than 5 more times.

    If it doesn't start there is something wrong with the blower. Since it was only lightly used I would imagine that your father had trouble starting it too. Something to think about anyway.
     
  5. 1grnlwn

    1grnlwn LawnSite Bronze Member
    Posts: 1,261

    New plug/fuel/air filter is a must. If you have starting insructions follow them. These two strokes are particular. My stihl instructions say to half throttle, choke for 1 pull and start with choke off. We start ours with no throttle choke no more than 2 pulls. You are flooding the engine. Getting the spark plug wet with gas. Once it's wet it will not spark. The only way to start it when it gets wet is A. pull plug and dry. B. Crank it alot with full throttle. C. Let it sit for 10 min. or so. Good luck.
     
  6. noseha

    noseha LawnSite Senior Member
    from MI
    Posts: 554

    1: Clean/replace the air filter.
    2: Replace the spark plug, only use BOSCH cRnI WSR6F OR 7547
    3: No throttle
    4: Full choke
    5: Pull it until it half fires
    6: Move the choke to off
    7: Pull it twice and it should fire.


    DOES IT NOT START ONCE ITS HOT. NEW PLUGS
     
  7. noseha

    noseha LawnSite Senior Member
    from MI
    Posts: 554

    1: replace the air filter gas line filter and gas
    2: Replace the spark plug, only use BOSCH cRnI WSR6F OR 7547 don't use champion
    3: No throttle
    4: Full choke
    5: Pull it until it half fires
    6: Move the choke to off
    7: Pull it twice and it should fire.

    only use high octane gas (97) and higher and stihl oil 50:1
    does it start hot? new plug will help
    sry about 2 post I don't realy know what happen
     
  8. habers

    habers LawnSite Member
    Posts: 3

    Thanks everyone! Plug is definetly getting wet, its a champion (will replace witha Bosch). Will replace filters, fuel and get some stihl oil too. Hope the dealer is open today :). Will let you know what I find out.

    Jonathan
     
  9. habers

    habers LawnSite Member
    Posts: 3

    The plug in there is also a CJ8Y
     
  10. sawman65

    sawman65 LawnSite Senior Member
    Posts: 751

    these blowers have allways been hard to start for people who have not been shown HOW to start a stihl br. when i sell one i take the customer back into the shop and show them.once you follow the directions it will start on the 3 or 4th pull every time
    1 put the throtle to half
    2 fully choke it
    3 pull till it "hits" (sounds like its gona start but dont)
    4 turn choke off
    5 pull till it starts
    even if in step 3 it dont run and stop TURN THE CHOKE OFF!!! it will flood. and go to step 5 if you have all ready tryed to start it and have flooded it pull the plug and pull till you see no more gas coming fron the spark plug hole.this will work every time in a blower that is in good running condition. good luck!
     

Share This Page