No spark on old agricultural tractor.

[mrsilv04]

Tractor: 1962 Case 630. In-line 4 cylinder.

It was running fine, shut it off, tried to restart, isn't firing.

Got out the test light, and with the key in the run position, the test light works all the way to the one side of the points.

However, I don't think I'm getting any spark jumping between the points when I crank. (It's too bright outside to see). I'll try to get a tarp to block the sunlight, to verify that.

What else do I need to check? Of course, it is sitting in a really bad spot.

 

[mechanicx]

I don't really remember points ignition systems lol. the points are on the lower voltage primary side so I'm not sure you should see much sparking there? Do you have no spark from the coil wire? I think you would want to check primary and secondary coil resistance and point gap.

 

[Quest]

check the coil primary and secondary for opens and shorts.

Also: never discount the possibility of a point failure (contact surface corrosion, oxidation, etc. can polish it with a bit of emery cloth or dress it with a point file and see how it goes).

You have to first get spark to go into the spark plugs before you can check your fuel mixture (carb condition). when in doubt: consider replacing the spark plug as a good measure also.


Q.

 

[big_impact]

maybe a coil issue? i would say so had the tractor got warm then died, but since you shut it off, i dunno

 

[mechtech2]

Get the engine where the points are closed.
Turn the key to 'run'
Manually open and shut the points and check for spark at the coil wire to the distributor. [Hold the wire end 1/4-3/8" from a good ground]
No spark?
Work you way back testing each component.

 

[mrsilv04]

I think I figured it out... When nothing makes sense, then do something completely different.

Swapped out the battery for a strong one that I just bought last fall, it fired right up.

It appears that the battery that was in it was putting out enough to turn the engine good, but it wasn't energizing the ignition.

 

[Trav]

Makes no sense really,the starting system takes a lot more current than the ignition.
Maybe you jolted something under the cap,make sure the condenser has good contact to the points.

 

[edhackett]

Something may be marginal in the ignition system. Cranking drops the voltage too low for spark. It's unusual, but I have seen it. Start with a through check of the coil and clean the points. I'd suggest a full electrical tune-up.

Ed

 

[mechtech2]

Originally Posted By: Trav
Makes no sense really,the starting system takes a lot more current than the ignition.
Maybe you jolted something under the cap,make sure the condenser has good contact to the points.


That's what I think.

 

[spasm3]

I would replace the condensor and check the points , make sure they are breaking. i have no idea what that gap should be for that tractor, if i had to just guess .020. I would look at the points if the look okay replace the condensor. if it still wont run then get the specs for the points. Coils do tend to work cold and not hot. if it starts cold and always dies hot, then the coil is suspect.

 

[mrsilv04]

With the old battery, I wasn't consistently getting spark at the points. One time, yes... the next time, no. It was inconsistent.

So, as I mentioned before, when nothing makes sense.. then try anything.

With the amount of cranking that I'd done, the old battery was getting weak. It would only take 5 minutes to swap it out, so why not. I'd already spent an hour and a half on it.

Put the new battery in, and it was running after cranking for less than two seconds. And the starter spun probably twice as fast with the newer battery.

There's probably something that is marginal in the ignition system that the newer, stronger battery was able to compensate for. I didn't tinker with the ignition at all between the time that I swapped the batteries.

I pulled out my records. I replaced the coil, points, condenser, cap, rotor, wires, and plugs in 1999. It sits inside of a dry shed. It has had less than 50 engine hours put on it since then.

This isn't a picture of mine, but here's one just like it. Dad thinks ours is a 1962. Grandpa bought it new.

 

[tom slick]

I had the same situation awhile back. Old tractor ran okay parked, 2hrs later wouldn't start and cranked a little slow. No spark from the coil so it was "I'll pull the points and condenser when I get time". Another worker tries to use the tractor, notices it is a little slow and hooks up a battery charger then the tractor started up immediately.