Scag Tiger Cub Cranks But Wont Start

Discussion in 'Mechanic and Repair' started by duffman301, Mar 31, 2009.

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  1. duffman301

    duffman301 LawnSite Member
    Posts: 20

    I have a Scag Tiger Cub with 21 hp Kawi and 48 inch deck. It is my back up mower and it has approx 1950 hrs. Today i went to the garage to service the machines and all of the started but the scag. I changed the plugs and cleaned the air filter and still it wont run. The motor does crank. If i spray started fluid into the air box the mower will run for a second and then die. I assume this means that the engine is not getting fuel? Maybe the fuel pump is bad? if anybody can offer me any guidance on fixing this problem i would appreciate it. The mower ran perfect when i parked it last fall.
     
  2. ALC-GregH

    ALC-GregH LawnSite Fanatic
    from PA
    Posts: 7,053

    Try tapping on the pump and on the carb. The float might be stuck.
     
  3. ed2hess

    ed2hess LawnSite Fanatic
    Posts: 12,963

    On some engines that have pumps you can pull of the line between the pump and carb and see it throws gas. Just take plug wires off. Did you say you put on a new fuel filter?
     
  4. DRBLawnBuster

    DRBLawnBuster LawnSite Senior Member
    Posts: 831

    Carb might need cleaned as well, if it starts when you spray stuff in there then it means its not getting gas. I would pull the carb off and clean it really good. Also you may wanna pull the fuel pump off and make sure thats all clean because its what helps push the fuel into the carb. With the fuel pump i belive there is a diagprahm gas kit and even if it has the slightest little tear it will be the differnce between pumping fuel to the carb and not ( as i have found out).
     
  5. EagleGrounds

    EagleGrounds LawnSite Senior Member
    Posts: 401

    Sounds like a snapped fly wheel, but you really need to slam on the truck breaks hard todo that. I broke my ztr's flywheel last year.
     
  6. J&R Landscaping

    J&R Landscaping LawnSite Fanatic
    Posts: 5,097

    Hopefully this post was a joke...

    I'll be the first with a couple dumb suggestions...

    Is there gas in the tank(s)?

    Do you have an shut-off valves turned on and selecting the correct tank?

    Next check would be the fuel pump check and then cleaning the carb like others have said. You might also try removing the fuel caps off both tanks. You may have vapor lock taking place.

    Did you make sure you have fuel comming through the new fuel filter you replaced? Sometimes, if you clamp the fuel line, you can get an air pocket in the fuel line that would cause the engine to not get fuel.
     
  7. borwicks

    borwicks LawnSite Senior Member
    Posts: 615

    If it fires up with carb cleaner or something similar its fuel related. If it was a flywheel it would not start. fuel filter, fuel pump. Start removing hoses from the tank forward where ever fuel is you know its got it. pull the bowl on the carb, check the float. this is all simple stuff. best of luck.
     
  8. EagleGrounds

    EagleGrounds LawnSite Senior Member
    Posts: 401

    No sorry, i was dead serious, i snapped the fly wheel lock in my ZTR engine last year, and i think it was because i made a sudden stop in my truck, which cause it to move and snap past the lock, causing the fly wheel lock to snap.


    sorry i forgot lock in my first post......
     
  9. ALC-GregH

    ALC-GregH LawnSite Fanatic
    from PA
    Posts: 7,053

    DO NOT take the plug wires off if your pulling the fuel line off. That's a fire waiting to happen if you start cranking it over.

    Do what others have said. Take the fuel line off the carb and crank it to see if fuel flow is there. If it is then the carb is blocked with fuel varnish. If you still don't have flow. Work your way to the tank.
     
  10. betmr

    betmr LawnSite Bronze Member
    Posts: 1,663

    My guess is you put it away with gas in it. That gas has formed Varnish & obstructed the fuel ports in the carb. Time to take the carb apart and clean it really good.
    At the end of the season, take out your owner's manual, and do what ever it says for storage. Save yourself a lot of trouble. Do it for ALL your machines. There is a reason they outline storage procedures.
     

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