Tractor running rough if at all

Donny Joe

New User
Case 430 Gasoline tractor was running good until recently. It now only starts after long cranking, idles rough and eventually dies. I have had the carb rebuilt,I put in new plugs,points, replaced the rotor, distributor cap, plug wires, drained the gas tank. Any thoughts or ideas? I know just enough to be dangerous. Thanks.
 
Inline filer or sediment bowl on it? It shouldn't have an inline filter. If it has one,somebody has put it on there and you need to eliminate it. Those things are made for a pressurized fuel system.
 
If they are for a pressurized system why do they work on a riding lawn mower with no fuel pump? And my 9N Ford had one in when I bought it and no problem.
 
When it does start...

Any exhaust smoke? What color, black, blue, white?

Any carb backfire? Exhaust backfire?

Does partial choke make it better? Worse?

Any way to do a compression check?

What do the plugs look like? Even though new, the color can be used for diagnostics. Look at all and note which cylinder each came from.

How is the spark at the plugs? Should be able to jump 1/4" from the terminal inside the boot to ground while cranking.

How does the distributor look? Any side play in the shaft? If the bushing is worn, the points will not be able to stay set. Is the centrifugal advance working? It should turn easily a few degrees then snap back when released.

If you can answer even some of these, it will help us better help you!
 
The bulk of the ones people buy at the auto parts store and stick in the line on tractors are made for use with a fuel pump,then they wonder why their tractor won't run for more than a few minutes after they put them on.
 
Bought this tractor in 1990 or 91, had trouble with an occasional speck of rust on the float needle. This is the second inline filter since and I bet it's ten years old and you're saying it won't work???
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The biggest trouble with in line filters is using small ones. Buy 3/8 filters and make it work, not the 1/4 inch ones. Think 1960s Dodge.
 
Another thought after I slept on it. Do you have an intake manifold leak somewhere? Cracked intake manifold? Gasket where it bolts to the head? Gasket where the carb bolts to the manifold?
 

This time of year any tractor giving me problems get the air cleaner checked right away. Oil bath air cleaners will freeze up and the ice will give you all sorts of issues if there's enough water in there from over the summer.
 
I agree use a big enough filter for the job, not a tiny one and have it restrict gas flow. Better to have too big a filter than too small and that is probably the factor that so many have with a inline filter not working.
 
Air breather was cleaned also.
Here in Texas we're still
experiencing the warm climate.
Thank you for your reply.
 
I was thinking about the same. Anyway to troubleshoot this? I haven't been able to detect a crack in the manifold yet. I'll doublecheck. Thank you.
 
I would take a close look at the mating surfaces between the carb and intake manifold. I have seen where someone didn't clean all the old gasket off of the intake tube and let air leak in at that point, thus reducing the suction within the carb. I have also had condensers new from box cause similar problems.
Loren
 
Thanks Steve...
I'll have to do a diagnostic on some of the items you mentioned. I haven't noticed any change in exhaust, no changes in the plugs, I DO have to "feather" the throttle linkage to eventually get it started, same with choke to keep it running. Seems like it could be loading up on fuel but not certain. . It ran fine after doing the major tuneup but after a few hours of running, it started acting up. I did get some bad gas that had water in it from a local store. I drained the tank, replaced the fuel lines and filters,cleaned the glass bowl, had the carb cleaned and new kit installed. When it does run for a few seconds the pipe from the carb to manifold is cool to the touch. Ill check the others you mentioned. Thank you for your help.
 
Do you have a propane torch? Put a hose on it,start the engine and stick the end of the hose around in different places with the gas turned on. If there's a leak,the engine will race when it sucks the gas in.
 
Thank you. The pipe from the carb to the manifold (intake?) has been cool to the touch when it was running. Normal?
 
Yes. Actually,if things are right,it's not unusual for that to get cold enough to have some frost on it.
 

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