Easy start pusher trl engine with mb carb, briggs 5hp

Discussion in 'Push Trailers' started by happycheapskate, Jul 29, 2011.

  1. happycheapskate

    happycheapskate Active Member

  2. happycheapskate

    happycheapskate Active Member

  3. happycheapskate

    happycheapskate Active Member

    Improved tank [​IMG]

    Now that's better! I made a tank bracket out of a piece of 1.25" flat stock, bolted to the fan shroud with 2 1/4" machine bolts. The tank is a baby formula jug zip tied to the stock. (there are pairs of holes drilled in the stock for the zip ties to go through. Make SURE your tank does not move!) The fuel line runs through the tank bottle near neck, and has a worm clamp on the end for a weight. The end is slash-cut and has a small notch cut out of it to prevent suction locking to the tank walls. It can run to the very last of the tank and holds 1/4 gallon. The breather hose goes in the tank 1" and has a cigarette filter poked in it for a breather filter. One off the ground will work if it isn't wet or burnt. I tried a water bottle from the $1 store but it cracked when I drilled it. Gatorade jug would also work like this and be clear to see fuel left. Next is a stainless steel water bottle. They are $5, and you can drill the proper hole and fish a car tire valve through there! (remove the core and it's a fuel barb!) If you can, use a tank with a lower fuel barb, tank such as off a lawnmower, and make sure the fuel does not leak on the motor or ignition system. That is why these hoses are up high, just to be sure. Small tractor or Pocketbike tank *might* work, with at least 2 brackets. Don't make it too heavy or it will bind up the shroud and pull start or bounce the tank.

    http://www.hyperparts.com/datapics/s1001c1003/images/items/184900.JPG example mower fuel tank replacement, $20 http://www.hyperparts.com/wc.dll?ctwp~getitemsearch~1001~1003~1~part~184900

    Pocketbike tank $15 [​IMG]
    Last edited: Aug 6, 2011
  4. srdavo

    srdavo Active Member

    That engine sounds good!!

    Mighty Crafty fuel tank ideas!!!
    (I'd want a "Got Milk" sticker.....:jester:)

    heh.... it's almost a shame to scrap out a good rear-tine tiller!
  5. happycheapskate

    happycheapskate Active Member

    Thank you. I won't be scrapping the tiller. I use it on a mtn bike trail and in my yard. The original carb failed after the tank rusted and some debris got into it. It was a Craigslist find. These motors are very common, but the original carb and governor system were designed for stationary equipment or yard tools, not go carts and stuff, so this is a good conversion.
  6. happycheapskate

    happycheapskate Active Member

    Here is how I made the carburetor mount, using a motor bicycle intake tube, and the original tiller carburetor. These are common, and you can test the original carb on your motor for fit by removing it and checking the size of the hole from the back of the carb to about 1 or 2 inches out. http://motoredbikes.com/album.php?albumid=1441&pictureid=9614 See album "miscellaneous" for more.

    Original carb was quite a bit like this: http://www.quickieparts.com/briggs-and-stratton/images/498298498298.jpg
    The gasket for it looks like the one on the right with the round hole. The screws for the carb go in the two holes farthest apart.
    This carburetor sucked, because it required a lot of use of the choke to start and did not start easily. Also I think it's governor linkage was overly complicated and it was wasteful of fuel at low speeds.

    I used Loctite brand epoxy, that looks like this (it comes with 2 nozzles so you get 2 uses, best epoxy product at the general stores!) : http://www.loctiteproducts.com/img/products/big/epxy_5min.png
    [​IMG] This stuff is incredibly powerful, so use gloves! Beware that it may run also! After gluing the parts, put them over some cardboard or newspaper, and let sit in a cool dark place for 1 day. Then set in a warm windowsill 1 day to fully cure. It will be kind of yellow and very hard when cured.

    You can salvage the original filter box and filters if you want, by making a flat plastic plate, drilled for the 2 carburetor filter-mounting screws, and a hole at least as wide as the carb venturi entrance/ intake manifold tube hole, between them. Then place the filter and cover over that and mark for screw holes for the cover, and outline the filter cover to trim the plastic plate down if necessary.
    Last edited: Aug 7, 2011
  7. happycheapskate

    happycheapskate Active Member

    Here is how the governor works now! It is simply using the original governor to activate a kill switch, which keeps the engine from accelerating. This is important because you don't want the gov. vane flopping around in there, and you need a rev limiter because the engine load can change very quickly (including when starting downhill or pulling the clutch in for emergency stop) [​IMG] http://motoredbikes.com/picture.php?albumid=1441&pictureid=9626

    The white tube is a piece of bic pen, with a zip tie run through it and around the screw which used to hold the gas tank support/governor linkage plate. The spring is from the governor system, used in the same location on the arm as originally. The gov arm now does not control the throttle body, so it is one less thing to go wrong on your go-kart or motored bike system.


    I made the contact arm from a wire coat hanger, but it would be better to use an aluminum or steel flat bar that you can easily bend and drill. It is mounted under the right rear engine mounting nut, so it grounds to the engine mount and frame.

    The disadvantage to this conversion is that the governor no longer accelerates the engine/opens throttle when engine speed falls due to loading, but the ADVANTAGES to this conversion are that the engine throttle valve/slide is precisely and instantly controlled by the hand and cable. A v-brake lever or twist throttle, a "thumbie" shifter off old bike, even a gripshift shifter would work well.
    Last edited: Aug 7, 2011