MF 65 no fire?

[doxford jim]

Tractor Manual Search - Yesterday's Tractor Co.

 

[Soundguy]

did you replace the correct coil. there are coils that are marked 12v that need a resistor, and there are coils that are 12v that do not need a resistor. if you put a coil not needing a resistor in a system with a resistor, you may have weak spark.

if the coil is correct and you can run it hot wired.. then check your wiring and connections from battery to key, and thru resistor.

 

[lipripper]

Thanks all for the help. Actually I have 3 manuals for this tractor ( well, for a Massey Ferguson 65, not necessarily my doctored up one ) Two of the manuals are for LP and diesel models only, and the 3rd has only 6v info in it. I did get a manual on CD to put in my computer also, which is the closest I've got so far as to the actual make-up of mine, but it appears to be a "bootlegged" copy and the print is horrible. Thanks for the links to some more, eventually I'll gather enuff to put Humpty-Dumpty back together again!

Soundguy, it will not run hot wired, which I believe eliminates the resistor. Could that mean I bought a coil that needs a resistor and it is getting too much juice?If so,would it spark anyway?
I'm about sold on the out of time problem(only becuz I've tried everything else),and that will be next weekends project. I just can't wrap my mind around the notion of the plugs not getting juice, in time or out of time.In my mind I thought that timing was an issue of spark and fuel not being at the same place at the same time, not no spark at all, although I've been wrong more than right!

 

[Soundguy]

a 6v coil will run on 12v, but it will heat and eventually thermally damage the coil and points... so if it won't run hotwired, AND you have checked that the points are opening and closing, contacts are good, and that they are not shorted, then I would look at timing. Many times a jumped time one will backfire

 

[Jerry/MT]

Ok here's where I'm at after today's tinkering.

Yes I did replace the points,but didn't remember removing or replacing an insulated washer. And the kit did not come with one.Does it go beneath the points, above them?
All those ?s are relevant, but today I did the " hot wire " jump from battery to coil as mentioned above, to no avail.

No spark from a plug removed(as if I was testing for spark at plugs) and "jumper wire" to coil.
No spark coming from coil wire to distributor ( the bigger wire that is like a spark plug wire ) no matter how I try ( jumped or regular wired)

With volt meter on pos of coil and grounded, with key on=12.4v.......... While cranking dropped to 9.3-10v.
Resistance between pos and neg of new(and old) coils were 3.4ohms
Resistance between the in and out (?) of the resistor before coil =2.2ohms

I have no idea what ohms/resistance/ or any of that means, had my neighbor helping me.

Getting close to calling the ole "mobile mechanic" and pay him by the hour to unfangle things.
Still have a pertinent question>>>>>>> When I removed the distributor to replace points, I was pretty careful to put every back in the same order(firing order,points at same cam on dist,rotor button pointed at same wire,etc), although I could've missed by a mile.. If I missed by a mile,would the coil not fire? Or would the fire stop at dist? Any more ideas are welcome

I'm perplexed why you have a resistor with a 3.4 ohm coil. if the resistor is in series with the coil than the total primary resistance is 5.6 ohms total and your primary current would be around ~2.2 amps instead of ~3.6 amps and that would lead to a weak spark. As the resistor heats up, the resistance increases and reduces the current even more. You do not need extra resistance with this coil as it is a "real" 12 v coil. A "12 volt coil that required a resistor" would have~ 1.6 ohms resistance

I would pull any plug wire and hold it near a good ground and with the ignition switch "ON" , crank the engine over. You should see a FAT, BLUISH-WHITE SPARK, the color of lightning. Anything less is a poor spark then pull the resistor out of the circuit , connect the remaining wires and repeat. Did the spark change?

You say you removed the distributor so make sure you got the timing correct when you put it back in. If you don't know how to do this, ask an I'll give you a simple procedure to do that.

 

[Kenneth S]

I told him to hot wire the coil directly to the battery, still no spark what so ever when cranking. It's either a bad coil, something in the distributor, or a bad coil wire. Something else to check, make sure the wire going from the points to the coil is not grounding out somewhere.

 

[Jerry/MT]

I told him to hot wire the coil directly to the battery, still no spark what so ever when cranking. It's either a bad coil, something in the distributor, or a bad coil wire. Something else to check, make sure the wire going from the points to the coil is not grounding out somewhere.

OK .Check the ground at the battery and at the distributor. Make sure the points are not burned, corroded, or oil covered and are opening and closing.

 

[lipripper]

Jerry/MT I'm with ya on the resistor in the wiring to the coil, but I left everything the same as it ran like a top. My shop mechanic ( we do underground utilities and grade(road) work and we run Caterpillar,but) he is an old tractor fanatic so I pulled him to the side and got the lowdown. What I believe I'm gunna do is pull the generator/voltage regulator and associated BS, run a straight 12V alternator, do away with the resistor, replace ignition relay,and reset the timing.. Thanks guys for all the input.

 

[Soundguy]

if the gen/reg is working.. no need to scrap just because.