Tecumseh snowblower carb on a lawnmower?

Discussion in 'Mechanic and Repair' started by ackack, Nov 6, 2018.

  1. ackack

    ackack LawnSite Member
    from West TN
    Messages: 92

    ke many, I have struggled with the flaky Tecumseh carb on my Toro lawn mower. My main problem now is that it won't prime after a bulb replacement (running fine before the replacement.) So I asked myself, is it possible to do away with the primer and add a choke? I examined a Tecumseh snowblower carb that has a choke ... see below. Some mod would be required but the snowblower carb sure resembles the lawn mower version in many ways. As far as mods, a couple things stick out: 1) the fuel nipple is pointing the wrong way. Maybe it could be turned or the hose could be curved to reach it, 2) there is no red straw sticking out the back .. how crucial is that odd lookng piece? Briggs & Honda don't have them, and 3) there is no outlet for a hose to return "whatever" to the engine ... not sure what is the purpose of that arrangement. What do you guys think?

    T carbs.jpg
     
  2. BigFish

    BigFish LawnSite Platinum Member
    Messages: 4,680

    It absolutely will work. Obviously ya gotta manually choke it. The red tube is jes the bowl vent. The fuel ell can be removed and pressed/epoxied back in place if ya need to.
    But why go thru all that, all ya gotta do is fix yer carb with a couple of new O rongs on the main nozzle. Basically clean the main jet/bowl nut, push out the nozzle tube from inside the veturi and dig out the small O ring that is stuck in the hole ya just popped the nozzle outta.
    My 'puter took a chit on me and I lost ALL my saved small engine links, and fav. folders, etc. so can't hook ya up. But if ya google tecumseh svc man. it has the skinny on them carbs.
     
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  3. Walker56

    Walker56 LawnSite Silver Member
    Messages: 2,020

    sjessen, DXN1EL and hort101 like this.
  4. hort101

    hort101 LawnSite Fanatic
    Male, from S.E. New England
    Messages: 13,881

    Dang y2k computers revenge:wall
    Hope you can get some back
     
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  5. ackack

    ackack LawnSite Member
    from West TN
    Messages: 92

    I did all those things, new o-rings, clean jets, even ultrasonic cleaner. New primer bulb (OEM) and circular clip holder ... still no prime. I have had it apart many times just to double check everything. Plus, it was running & priming fine before I attempted to install a new bulb. That's why I am running this by the forum as "Plan B." This is a backup mower so I can experiment with it.

    I have marked the top tube piece with a red dot. The snowblower carb doesn't have this piece. On the lawn mower carb, a short hose connects to it and goes back into the engine. I think it sends spent gas vapors back into the engine to be re-burned or something. How critical is it to have that function? Thanks.

    T carb top tube.jpg
     
  6. Walker56

    Walker56 LawnSite Silver Member
    Messages: 2,020

    The crankcase breather hose from the engine goes to that port. You can, if you want, drill a hole in the inside of the air cleaner housing and install a barb fitting and attach the hose to that. Do not block off the hose.
     
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  7. ackack

    ackack LawnSite Member
    from West TN
    Messages: 92

    I think I see what you mean ... where the red dot is??

    tecum air housing.jpg
     
  8. Walker56

    Walker56 LawnSite Silver Member
    Messages: 2,020

    It has to be anywhere on the inside portion of the air filter, not the incoming air side
     
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  9. ackack

    ackack LawnSite Member
    from West TN
    Messages: 92

    Here maybe (red dot)?
    BTW, do you know why the snow blower carb does not have a crankcase breather port/hose? At least I can't see one in the picture I posted previously.

    t collar.jpg
     
  10. Walker56

    Walker56 LawnSite Silver Member
    Messages: 2,020

    Probaly because the engine it was made for has an external vent. As long as the barb you install is on the filtered side of the air cleaner, you will be fine.
     
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