Rebuilt Farmall Cub has Fire but won't start

   / Rebuilt Farmall Cub has Fire but won't start #31  
DJ has it right! Complete MACHINE SHOP re-bore!--- and hope the block can be saved. IF someone who didn't know what they were doing messed up the bores,-- it may have to be bored way out then sleeved back to standard specs.pistons. (very expensive, last count I had it was around $100. per hole), or find another block to start with and have it done up the right way to start with.
The machine shop will make the bores are square with the crank, ( something you can't do freehand), also they mic. the bore and get the right clearance along with proper crosshatching.
Not many options here. It depends on how much the cub means to you and how much money you want to spend on a 9 hp. cub and what you want to use it for.
Final option is to sell it for parts. thanks; sonny580
 
   / Rebuilt Farmall Cub has Fire but won't start
  • Thread Starter
#32  
ok i put the old pistons back n and it runs but misses i will run perfect on low idle but *** soon as i give it gas it starts sputtering and dies
 
   / Rebuilt Farmall Cub has Fire but won't start
  • Thread Starter
#33  
i need to ask a question ive put several rings in pistons u put the oil rings on first then your next rings are the second ones and the next one s are the first one right now the rings i got with this kit has spring around it and 2 little rings thin rings ok the old set has a spring and one wide ring thats the ones that came with the tractor i also know the old ring had a grove in the top ring and a dot on the second ring and one wide oil ring and one band spring the aftermarket doesnt.
 
   / Rebuilt Farmall Cub has Fire but won't start #34  
Some ring sets will have a slight bevel on the compression rings, that should face down.
It has the "new" style oil ring.
Have you fitted your rings to the bores?
set the rings in before they are on the piston to check the ring end gap?
With it running on the old pistons and rings, where the old ones a .020 or .030 overbore pistons?
 
   / Rebuilt Farmall Cub has Fire but won't start
  • Thread Starter
#35  
ok what about putting ten thousand over on a standard piston and file the end down to 4 thousand
 
   / Rebuilt Farmall Cub has Fire but won't start
  • Thread Starter
#36  
because im at ten thousand now on the bore with the new rings
 
   / Rebuilt Farmall Cub has Fire but won't start
  • Thread Starter
#37  
has amny one ever put stp oil treatment on the piston to see if that sticky mess will give it compression at least i know its my rings
 
   / Rebuilt Farmall Cub has Fire but won't start #38  
It is poor practice as the ring sits out so far on the lands and the piston will have room to rock and slap against the cylinder bore.
That said at one time you could get ring shims, I haven't seen any in quite a few years.
Here is a similar situation from a different forum;
Piston Ring End Gap - Farmall Cub
 
   / Rebuilt Farmall Cub has Fire but won't start #39  
Cubs will pop and fire 180 out static time it and go from there points are reliable and plugs are cheap auto lite 286 and see what happens. A cut will also run on 3 holes if the cap is bad so check the simple things out
 
You must log in or register to reply here.
 

Footer Links 1

Top