Re: H4 magneto condensor to short to reach grounding screw

560Dennis

Well-known Member
Location
Madison,Ohio
Change Points and condenser ,caps ,rotor, wires ,and coil is probably shot and moisture gets in it. ,
Iwould also make a new wire from condenser to points insulation is shot.
If you have done much to the ignition for 30 years time to change everything .
 
I'm thinking you are right.

Just gets me that it has run fine all this time then out of the blue it quits!

I'd just like to figure out the actual problem is but sometimes what I like to call the "shot gun approach" is the best option. If going through it like I did the last time lasts as long I'm thinking I won't be needing to do it again! Maybe I should leave instructions for the four year old grandson!!
 
Well here's hoping I have this problem fixed.

I decided to see what local NAPA dealer could supply and to my surprise the only thing they could not supplly was the coil cover and other than the coil they had to get from the warehouse everything was on the shelf. Only took a few hours to get the coil from warehouse!

One thing I had noticed when checking things out but could not find right off a spec for was continuity from the little bump of solder in the coil to ground. Everything I have learned over the last 50 some years said there should be some reading using an ohm meter.

Testing the wire that goes from the points to the ground strap I was getting very low ohms, around 0.5 to 0.7 but nothing on any scale for the output solder bump.

First thing I did when I got the new coil was to make some readings to compare with the old coil. About the same on the wire from the points to ground, right around 0.6 ohms. But on the new coil going from the ground strap to the output solder bump I now had a reading of 15.5 K Ohms. That was encouraging!

As I believe I had mentioned before I was not too impressed with the spark the original parts were giving. So after installing the new parts I hooked a plug wire and an old spark plug to the coil output and did a bench test. Spark seemed good so I opened the plug gap up to about 3/8 inch and tried again and if anything the spark was even better!

Reinstalled the mag on tractor and hit the starter and it fired right off. Now the only thing left to do is run the tractor for a couple hours mowing to see if any problems come up. As the temps are suppose to be in the 90's for the next week I think I will pass on that for now.

If anyone wants the NAPA numbers these are what I used:
IC1851 ignition coil
IH201 Condenser
IH301 Rotor
IH351 Cap
CS1601 Contacts/points
 

Just a short follow up to the last post.

Used the BN to mow about 5 acres or a two days time in fairly warm weather, upper 80's, and never skipped a beat s I'm pretty sure it's good to go for a few more years.

Believe the problem was in the coil in the magneto as everything else tested fine.
 
Just came in from another few acres of mowing and BN ran great. Now if the dummy running it had not hit a stone and bent the center blade on the Woods 306L was paying closer I would have been done much sooner!

As for the BN it never missed a beat so I'm thinking this tractor could out live me.
 

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