SMTA Won't Sart

My SMTA will not start. As I crank it over it will pop but that is as far as it will go. Any suggestions as to what to check or do?

The first issue is to determine if it has moisture in the distributor cap. (very common in changing weather)
The second is to make sure the points are clean and smooth, and set to .020" on the high point of the distributor cam. (It makes no difference which.)
The third is to determine if it is getting full flow of gasoline to the carb. There should be Dog taking a leak amounts of fuel at the point where it connects to the carb (use a clean can)
The forth is to make sure the timing is set correctly to TDC at #1 cylinder, and (usually rotor points to 1:30 pm.
The wires are:
2-1
4-3
Looking forward at the cap.
Good luck, JimN

As Jan has pointed out are the common things to check . Now if you find that you are indeed out of time then yo are going to have to dig deeper and my guesstamation would be that (1) you sheared the timing gear key as this has been a problem with any of the older tractors with a cam driven hyd. pump (2) is that the cam gear is maybe missing some teeth and this has allowed it to jump timing. First see if ya got good spark and the fuel flow out of the line at the carb should be a full stream the size of the line . IF you did shear the key in the cam gear make sure that you get a hardened key or you'll be doing it again. Went thru this with one guy twice in one summer on his M/TA as he had keys in a jar that someone gave him and they were soft and when he went to use the hyd.'s and lift and emplment she would hit the end of the stroke on the cylinder and the tractor would just shut off and the call would come , HELP MY TRACTOR JUST QUIT IN THE FIELD . By the time i got there he had it towed back to the barn and the ft. end off and i had to do the rest .Got it apart the second time and here he comes with his glass jar of keys . Told him that the first time was my falt for letting him give me a soft key , This time i ain't putting it together with one of them and to either get a hard key or he could figure out how to do it the next time . This guy was so cheap that he would not even buy the gskts and since someone gave him all these rolld of gskt. paper he would make the gskts . That would take him a day or two to make the gskts. and i would have to make a second trip to finish the job . Till i told him that the new policy waqs there would be a second service call charge plus milage plus my hourly rate from the time i left the shop till i got back and that was going to cost more then just make the 7 mile drive to the dealer and get the parts .

When you get No1 piston to TDC on the compression stroke Look to see where the rotor is pointing. It should be at the No1 plug tower. Hal

When I first got my SMTA fired up it didn't start well. Realized it was blowing air out the intake. I pulled the hydraulic pump and distributor and found the cam gear was loose. When I pulled the front cover I found the keyway in the end of the cam shaft was broken out. Another time I had the distributor off and changed points and condensor. Put the wrong screw in to hold points down. When I fired it up, or tried, the distributor shaft wasn't turning. It sheared the pin in the drive gear on the end of the distributor.