My M Eats Condensers

[SuperABen]

I'm a little more than frustrated with my John Deere M.

It will start and run great with a new condenser. It will run will for about an hour before it will shut off straight without any spark. It will not start back (even cold) until I put in a new condenser.

It has started literally eating condensers. I have had to put one in after running it six hours, aftermarket A&I, then another one after an hour, Standard DR60, and then a third one. The third time I bought a second brand new coil (Standard 6volt) with the condenser (Standard DR60). It has lasted maybe half an hour of running time.

It is 6 volts. It has a rebuilt generator and relay. I have put all new distributor parts in it: cap, wires, breakers. It has a great battery charge.

I am more of a magneto guy than a battery ign guy.

For the record, it is not carburetor related. It has done this same problem for two times already, and a new condenser fixed it right up.

There is something wrong in the ignition system. I'm tired of feeding this thing condensers. Has anyone had a similar issue?

Is it the ignition switch?

Is it there a wiring problem?

What condenser and coil brand do you folks use?

Ben W.

 

[Husker44A]

I would think its a bad voltage regulator. John T or others will chime in. It's not your switch, nor a wiring problem. It's not the "brand" that you use either.

 

[teddy52food]

Check the voltage after running for a half hour or so. If it is over 7.5 is may be too high. If not you are just getting bad condensers. I have a tester and find some leaky ones right out of the box. Have someone test the next one warm and cold before you put it in.

 

[James Howell]

Thankfully we"ve never had this problem with "Sparky" our 51M, but initially with "Rusty" one of our 51 MTs.

We"ve also had the same trouble with both "Sam" and "Mac" our other two 51 MTs, but not as much as "Rusty".

New ignition switches have been installed.

New cut-outs have been installed.

New wiring has been installed.

New coils have been installed.

We have used John Deere and A&I condensers in the past.

We now use both condensers and coils from NAPA.

Bought 3 condensers within the last month to replace my "on hand" stock.

Sorry that I don't have a solution for you, but I do know what you're going through.

Electronic ignition may be suggested by others, but that will be your decision.

Hope this helps.

 

[SuperABen]

James, thanks for the info. What helped the best on your tractors?

I figured the last time that an auto parts store condenser and coil would be best, since antique car guys would raise all sorts of noise if the store sold junk.

I'm considering an ignition switch, but I can't decide if that is something that would cause the system to burn parts without me noticing other damage or a run down battery.

Ben W.

 

[SuperABen]

Thank you to everyone for their responses so far.

I tried the tractor tonight. It will run 50% of the time on what sounds like one cylinder, one fire per minute. Sounds like a dying hit and miss engine.

It is getting plenty of fuel.

How could a condenser be burned out like this? Didn't the old machines used to last forever on the original condenser?

Ben W.

 

[James Howell]

I am hoping that all condensers are not manufactured by the same company and just packaged in different vendor boxes.

Keeping in mind that a condenser may be "faulty" right out of the box regardless of its price or brand, experimenting with different "brand name" condensers has helped best.

A new ignition switch will not hurt your electrical system and they are not very expensive.

The only problem we've had with an ignition switch burning parts was my fault.

Turned the fuel off on "Vernon" our 56 Model 70 and let the fuel run out in the carburetor.

Forgot to turn the ignition switch off.

The points were closed when it ran out of gas and they were burned.

At this point all of our condenser problems have been limited to the MTs, especially "Rusty".

No condenser problems with the A, M, 40, or 70s.

 

[James Howell]

If [i:654c4848f0]"It will run 50% of the time on what sounds like one cylinder"[/i:654c4848f0], then you might consider checking the valve springs.

Once again poor old "Rusty" had a broken valve spring and was running rough.

Replaced the valve spring and it ran good until a different valve spring broke.

Hope this helps.

 

[M-MAN]

Not trying to be smart but a bad condenser doesn"t half run that I"ve ever seen. Any decent meter will read the mf"s of the condenser & you definitely need to test your"s. What I suspect is you have a bad connection & when you replace the condenser it is temporarly fixed just because you disconnected and reconnected everything. Could be the dist wire, a plug or coil wire, the dist insulating terminal, rotor, weak ground, etc. I would check those valve springs and lash as was mentioned as well as running voltage.

Capacitors usually fail due to excessive voltage or amp draw.

 

[Hotflashjr]

My MT ate condensors for a while. I had what I believe to be 3 issues. First was junky condensors. Some are just bad. Any time I find a NOS condensor on ebay or at a swap I try and buy it. If you look at James' fourth picture there is a stud coming out of the distributor with a red wire going to the coil. Replace this stud. Mine had lots of wear and corrosion on it. It is a cheap part and usually overlooked. Last was my ignition switch. The cardboard the resistor wire was on had all but rotted away leaving the wire to bounce around, break, recontact itself, etc. I soldered two new resistors onto the switch I found on ebay.
Resistors replaced on M series switch