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RV RX

The fairbanks morse model RV appeared shortly after the debut of the Model R. Unlike the model R with its wound armature design and exposed horseshoe magnet, the RV was a step towards the modern age. It featured a stationary coil with more modern magnet metallurgy and fewer moving parts.  It no longer needed a carbon collector brush and was not subject to the usual woes of sticky goo seeping from the windings. The early models used a bakelite coil and the later versions used a hotter tape wound coil. These were much easier to service than their predecessors.  The biggest cause of failure is the usual, barnacles on the points. They are a best serviced by removing the stationary point and the lever. As always, get the jagged edges off, then polish to a mirror finish for long life. The other issue is the famous flat metal condenser. These as a rule are Bad Bad news. Seldom will find a good one. Save the new old stock devices for the curio collectors.  They typically develop electrical leakage, even sitting on a shelf causing pitted points and a wimpy spark. Always check for electrical leakage first, then capacity. It should come in around 0.2MFD.  More to follow on RX for this debacle. These when in repair are actually very hot and were used as OEM by Allis Chalmers(Model RV4),John Deere(DRV2A,DRV2B) and Fairbanks Morse (Model RV1) on their Z engines.  Here are some general instructions to keep yours alive and well with service and parts info to follow.

The RV4 was used by Case and Allis Chalners as OEM and probably would have worked well in the day, save for the condenser issues. Mechanically, they were robust.

Here is some factory service information to keep yours alive and well.

The best way to check the condenser is to use an actual automotive/ignition condenser tester. Always check for electrical leakage first, then check for capacity. A leaky(and defective) condenser will give an overstated capacity test result. If it is leaky, replace it, or will cause pitting at the points and a wimpy spark. Automotive condenser testers will charge the condenser with a high DC voltage (100-250 Volts DC usually) and determine if the device will hold the charge. A leaky condneser will not hold the charge. If it is an original flat metal condenser, it is most likely leaky and should be replaced. Stay clear of new old stock capacitors. These in particular can develop leakage sitting on a shelf and unlike wine do not improve with age. They were not well sealed and used paper as an insulator that soaks up moisture nicely. leave them for the curio collectors. Modern units use polymer plastics like Mylar(polypropylene) and should be nearly indestructible. the Sprague/SBE/Vishay "orange Drop" devices work well.more to follow:

This is an Orange Drop rated at .22MFD 400 Volts DC and works well. These are readily available from electronic suppliers. This one came from TubesNMore(formerly Antique Electronic Supply of Tempe, Az.The polypropylene film insulated devices are the most robust for handling spike currents that will occur when the points open. An automotive device would work, except that there is not much real estate where it needs to live. The ring connector goes to the ground like the original. the lead extending from it should be pointed at the coil leadout strip the same distance as from the grounded original condenser case to serve as a safety gap once in place. The other leg should be spliced and soldered and fitted with an insulating sleeve to make a connecion to the terminal on the side of the coil where the breaker lead attaches. This makes a good installation.the capacitor is wrapped with fiberglass tape to minimize vibration damage.

This is a good place to start.  get the points clean and polished to a mirror finish. The 110 volt test light/continuity tester looks like a good way to get a shock.Do not try at home! Best to use a multimeter for safety's sake.

Most parts are no longer made, but many new old stock parts are out there and there are some retrofits for the coil and condenser.   The pictures are helpful for reassembly.