Stihl BR 420 Blower Flooding

Discussion in 'Mechanic and Repair' started by slawn, Jul 19, 2007.

  1. slawn

    slawn LawnSite Senior Member
    Posts: 326

    I have a 420 blower that keeps flooding. I've took it to the dealer twice, and they have yet to find the problem. They last time they said it was probably trash in carb. It ran on the first yard this morning, second yard wouldn't start. I tried several more times throughout the day, flooded every time. Any suggestions?

    thanks
     
  2. JHugh

    JHugh LawnSite Member
    Posts: 84

    What did the dealer do the two times? Did they just clean the carburetor or rebuild it? It may be leaking past the inlet needle in the carburetor. The metering diaphragm could be getting stiff and sticking the needle open. The metering arm may not be adjusted to the correct height.
     
  3. slawn

    slawn LawnSite Senior Member
    Posts: 326

    They just cleaned it. I think I'll get a kit and rebuild the carb see if that solves the problem.

    thanks
     
  4. Breezmeister

    Breezmeister LawnSite Bronze Member
    Male, from South Jersey
    Posts: 1,488

    Probably trash in the carb ? Sounds like the dealer or the mech dosen't know what the problem is.......With out knowning how old your blower is, do you have a good fuel filter in the tank ? If yes, it's not the carb, do you have a air filter on the carb that is not letting dirt pass, if yes, it's not the carb.
    More then likely, it's the rings sticking or maybe the seals on the crank. If you have a "few" hours on that blower, if you can check the compression when it's cold and then when it won't start. You should have a min of 90 psi
    at all times. You can tell if the seals are bad by taking the recoil off and see if you have any kind of leakage and there is another one of the fan side, that one is alittle more work to get to :) The seals help the carb to breathe
     
    ericg likes this.
  5. MowerMedic77

    MowerMedic77 LawnSite Bronze Member
    Posts: 1,164

    I would have to say if gas is pouring out of your carb(flooding) then it is a carb issue:hammerhead:

    Most Sthil BR400s have a Walbro HD carb this has a large diaphragm gasket that tends to wear out and also I have seen the needle stick in the carb body. If your dealer rebuilt it(or fixed it:confused: ) and it still is not right take it back.

    Or if you have some mechanical skill and you just want to replace the carb post the #'s off of the carb itself and I can tell you what to order and were to order it so you can just replace it and you will be back up and making money.
     
  6. Breezmeister

    Breezmeister LawnSite Bronze Member
    Male, from South Jersey
    Posts: 1,488

     
    ericg likes this.
  7. MowerMedic77

    MowerMedic77 LawnSite Bronze Member
    Posts: 1,164

     
  8. Breezmeister

    Breezmeister LawnSite Bronze Member
    Male, from South Jersey
    Posts: 1,488

     
    ericg likes this.
  9. DSIM

    DSIM LawnSite Senior Member
    Posts: 440

    I know this is an old thread but I'm currently having the same problem now. I have 2 420's, one is two years old the other 6 and just last year they both are doing the same thing. After use the next day the air filter is full of gas and the spark plug is wet.
    I have to remove and dry then they will start back and run great. This progressively got worse and worse until it got to where it is now.

    There were some suggestions on here but no followup as to what the solution was.

    I took the carb off of one and sprayed it with cleaner and blew it out but that didnt change anything. There must be blockage somewhere I would guess.

    My frustration with these makes me want to sell and buy Redmax but I dont want to sell this problem to someone else.
     
  10. ed2hess

    ed2hess LawnSite Fanatic
    Posts: 13,079

    I got several and they all flood but not to the extend you describe. Yours sounds like the carb is leaking. Now that can be debris i the needle or can come from bouncing around. Also pressure builds up in the tank and I think that is a problem. We pull the rope about 5 times with the unit off before trying to start it. Then 3 times with no choke and usually they start. Seldom do we use the choke. I like these blowers but they do flood easily.
     

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