No Spark to plugs...please read and help

[bigdeano]

It's an old tractor, probably has a lot of hours on the engine. If the spark isn't going through the HV part of the distributor, it's probably out of time and the rotor doesn't line up with the cap terminals. Maybe the distributor gear is worn, or even the cam timing gear slipped a tooth. Like others have suggested, check the timing and make sure the rotor is pointed at the cap terminal when it sparks.

It stalled while it was running, so something failed.

 

[EE_Bota]

It's an old tractor, probably has a lot of hours on the engine. If the spark isn't going through the HV part of the distributor, it's probably out of time and the rotor doesn't line up with the cap terminals. Maybe the distributor gear is worn, or even the cam timing gear slipped a tooth. Like others have suggested, check the timing and make sure the rotor is pointed at the cap terminal when it sparks.

It stalled while it was running, so something failed.

Good point. I think is it time to address rotor position to be certain.

 

[Soundguy]

i'd be VERY surprised if both were not chinese.

there is an IC14 and an IC14SB same coil.. one is 50-60$ and is the gold line.. the other is 16$ or so and is the value line. black coil.. white printing.. other spendy coil has a decal on it..

both are oil potted coils.. oil potted coils handle heat much better than air, tar or epoxy potted coils, with respect to heat disipation.

running the numbers real quick looks like it's running with a 20% tolerance. I don't find that uncommon... lots of automotive electronics run 8-15v since charge votls will be as high as 14.4 to 14.7 in some cases, and at startup.. most electronics won't see over 10v usually.

soundguy

 

[Soundguy]

It's an old tractor, probably has a lot of hours on the engine. If the spark isn't going through the HV part of the distributor, it's probably out of time and the rotor doesn't line up with the cap terminals. Maybe the distributor gear is worn, or even the cam timing gear slipped a tooth. Like others have suggested, check the timing and make sure the rotor is pointed at the cap terminal when it sparks.

It stalled while it was running, so something failed.

did the naa use a fiber cam gear or metal one? I know on the N fiber gears were used.. and could strip out.


here's another thing to check in case it was or wasn't mentioned.. look at nose of hyd pump/tach drive and make sure it turns evenly and doesn't slip and jerk when cranking..

 

[Jerry/MT]

It is most like sized at the starting point toprovide the maximum spark voltage at the redued battery voltage and you just have the capability for higher spark voltage IF it's Needed at full battery voltage. Remember the coils only delivers enough voltage to make the spark no matter what it's rated at.

Another trick is to use a resistor in a parallel circuit that puts resistance in the primary circuit when the key is in the run position and when the key is in the start position, no reisitance is in that other circuit to the coil. Used to be common on Chrysler products and others.

 

[Jerry/MT]

dizzy wasn't snatched out of this machine was it?

with #1 on tdc comp stroke.. is the rotor pointing at the tower going to that plug?

has dizzy been repalced.. or parted together.. perhaps another advance? advance from the 00 to the naa are IIRC not compatible..

Usually, the advance does not come in at low rpm's like cranking speed. If the engine is timed "correctly" even with a stuck advance it should start but be doggey at higher rpm because of lack of advance. The OP is saying fat spark at coil high tension output and no spark at plug wires. So that would be an out of time situation. Did he time in on the exhaust stroke??????

 

[Soundguy]

It is most like sized at the starting point toprovide the maximum spark voltage at the redued battery voltage and you just have the capability for higher spark voltage IF it's Needed at full battery voltage. Remember the coils only delivers enough voltage to make the spark no matter what it's rated at.

Another trick is to use a resistor in a parallel circuit that puts resistance in the primary circuit when the key is in the run position and when the key is in the start position, no reisitance is in that other circuit to the coil. Used to be common on Chrysler products and others.

yep.. common bypass setup.

3 cyl fords run power straight to the coil.. in start and run power is thru a resistor wire. 6v coil on a 12v system.

 

[Soundguy]

only reason i mention advance is I have seen someone put the advanc off a different unit on.. that turns a different direction.. and the rotor would be pointing like halfway between posts.. op had good spark at coil tower.. and when hooked to dizzy. would get leakage from center tower of coil over to the screw terminal ont he cover of the coil as there was no closer gap for the spark to jump.. IE.. it was tracking along the coil top to find a gap small that betwixt the 2 towers.

I was just wondering if the op had his dizzy removed and rebuilt or something..

on another note. the later had the hex drive right.. but the naa drive is different? it's not a pinned setup is it? (slipped drive? )

 

[nj82tj]

I have yet to pull the distributor and look at any of thoes internals. I just picked up a new cap and dust cover to be sure. It did not start. The dust cover has the fiber washer on it. I tried to direct wire a second battery right to the coil, no different. Um, what else...points are gapped, I did check timing by pulling the plugs and using the thumb over hole method. Every wire seems to match nicely with the rotor. I did loosen the distributor and turn it about a 1/8" at a time just to try and get it to hit. No luck, it's now back in its original location. I replaced the condenser again while I was in there. No luck. I do however notice a weak spark at the plug (when grounded on the tractor just for inspection) when the starter is almost done cranking. I hadnt noticed that before. Still won't turn over though. I'm getting close to pushing her into the street and letting my neighbors pond take care it it...it's so frustrating because it makes no sense! Thank you again everyone for all your input thus far. If anyone else is bugged enough by this, feel free to message me and I'll give you my phone number so we can talk directly. I'm about out of options here.

**the weak spark I'm referring to is via the dist. cap**

 

[Soundguy]

back to no spark now?

and now she won't turn over?

sounds a whole lot like a bad battery.. bad connection.. poor ground.. or bad starter bushing making for an excessive draw.