8 HP Techumseh Starting Problems - need Help - Pictures

Discussion in 'Mechanic and Repair' started by 1966vette, Jun 12, 2010.

  1. 1966vette

    1966vette LawnSite Member
    Posts: 209

    Looks like the word is out on these tecumseh carbs:


    MTD Snow Blower w/Tecumseh Engine Won't Start


    the carb on that particular engine has a sealed passage with a check ball in it,after you pull the carb give it a shake if you hear the ball rattle give the rebuild a try if not save yourself some grief and spring for a new carb

    This Seems like good advice!
    If I had known this simple test, I would have cut my losses, saved my labor & the cost of a rebuild kit & opted for a new carb. Learning is never cheap! This will not happen it me again!

    Thanks again for all your help!
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Andy, A new carb will most likely solve the hard start issue. On the new carb set the low at 1 turn and high at 2, This is a good starting point then adjust from there. But, Have the air filter in place while adjusting.

    It's not a good idea using starting fluid for a prolonged time, It can wash the oil from the cylinder/rings and valves causing premature wear.
  3. Briggs Man

    Briggs Man LawnSite Member
    from Toronto
    Posts: 20

    A new carb will help but what about your piston or piston rings? ever consider putting a brand new motor on it ?perhaps a Honda one cannot say enough good things about a Honda engine
  4. 1966vette

    1966vette LawnSite Member
    Posts: 209

    Briggs Man,

    This is a carburetor issue. The ignition system and compression of the motor is excellent. I opt for a new chipper before I spring for anew motor.

    Honda is an excellent choice for a replacement motor & made in the USA.
    Only Honda & kawasaki engine are US made.
    The rest are either out of business or made in Mexico or off shores - per the John Deere Dealer
  5. 1966vette

    1966vette LawnSite Member
    Posts: 209

    I’m cleaned the wood debris out of the chipper & now it turns over much easier because it is not longer out of balance.
    I do not have the factory service manual for the MDT chipper so I looked up the proper torque on web at the enclosed link.

    Fine Thread
    Size Grade 2 Iron Grade 5 Iron Grade 8 Iron Aluminum

    7/16-20 (NF) 36 50 70 40
    1/2-20 (NF) 55 75 110 60
    9/16-18 (NF) 80 110 155 85
    5/8-18 (NF) 110 155 215 120

    The 9/16 NF bolt had 6 marks on it & LE in the middle.
    I applied anti- seize to the threads & started to torque the bolt to 110 ft lb & it broke at 60 ft lb.

    What’s the deal here?
    Could the bolt be defective or an inaccurate 30 years old Craftsman torque wrench?

    Very disappointing!
    Who is the bozo on this one?
    Me, the bolt or the wrench?
    However, the chipper wheel came off w/o a fight & I have a new 9/16 NF bolts with 5 marks which I plan to use and torque to XX ft lb.

    What should I torque this bolt to?

    Any advice will be much appreciated!
  6. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Andy, There's no bozo here just a mis-understanding.

    The fact that you may use a 9/16" wrench/socket to tighten a screw doesn't mean that screw size is 9/16". In most cases a 9/16" wrench size head is a 3/8" size thread shank, Knowing the unit your working on this is the case. So, Use the 30 ft.lb. spec listed for the 3/8" -24 NF screw and you should be good to go.
  7. 1966vette

    1966vette LawnSite Member
    Posts: 209

    Hello Restrorob!
    Thanks for a quick reply & and an excellent assignable cause!

    I also removed the rebuild Tecumseh carb from the engine, disassembled the float & did not hear a rattle when shaken.

    Too bad now the carb will have to be replaced.

    However, I plan to go down w/ a fight & add some fuel injector cleaner to the gas & run the chipper for an hour.

    If it still does not run correctly I will replace the carb.

    Thanks Again!
  8. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    No problem Andy !

    Many many people including myself have tried to revive these old carbs without success, Soaking for a month in a 5 gallon bucket of old school cleaner for a month (before EPA started in with water based cleaners) did nothing for it.

    Your best bet is to put the money for the injector cleaner toward a new carb and be done with it.
  9. 44DCNF

    44DCNF LawnSite Bronze Member
    Posts: 1,460

    This method helps with starting those style chippers. Set your choke and throttle accordingly. You first pull it over slowly to draw the engine up to the start of it's compression stroke. Some flail blades will flip over and you'll feel the resistance in the cord. Let the cord rewind, pull again to engage the dogs and give it a hard full pull to start it.

    Good luck. Give it more than one day to decide though, if you try the fuel cleaner soak. Run it each day for a few, working it through the rpm range and partially applying the choke (as much as it will take and still run well) at different speed settings.

    edit....my carb cleaning advice above isn't speaking to that specific style carb. It's worked for me on others though. Rob is surely right - I trust his experience.
    Last edited: Jun 13, 2010
  10. Ruben Rocha

    Ruben Rocha LawnSite Senior Member
    Posts: 577

    Rob is usually spot on. So....

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