Points woes

[brownfrog]

We repair vintage tractor magnetos and have had the same problem. Some aftermarket points are not usable out of the box. The contact surfaces sometimes are coated with a lacquer, shellac or even oxides that need to come off and the surfaces do not line up without some bending. Sometimes we need to do some filing to get the clearance correct.  Unless the rubbing block or

contact surfaces are worn away we recondition them. If there is a reddish copper coloured tinge when you polish the contacts that means that the tungsten or platinum contact surface has worn away and new points are needed. This is very rare in our experience.  Most service literature from back in the day describes using a fine sharpening stone or fine diamond file like an EZE LAP. We also use a Cratex stick. It resembles an eraser with abrasive in it and comes in various shapes and sizes and grit sizes. Red is medium and slate is fine. Order direct from Cratex.  These will leave almost a mirror finish that will stay clean in jig time.

[sutterhome]

Use the old points?

[brownfrog]

I believe that I would reuse them. A Cratex abrasive stick will Get them smooth and shiny, usually in 5 minutes or less. A smooth finish will stay clean longer than a rough finish. Start with the red (medium grit) then follow with slate (fine) grit. If very rough and jagged use a fine sharpening stone or EZE Lap diamond file then follow with a  Cratex stick.   We seem to reach for them in a daily basis in the shop or afield. A medium and a fine stick the size and shape of a candy bar is a useful tool if you have any rolling stock with points in your fleet. These work well for servicing relays, switch contacts and any surfaces that require electrical contact. Much of what we service is dreadfully obsolete and there are no spares for them. Sometimes our vintage fleet seems to get car sick. It performs well at home then has no spark when arriving at the fairgrounds, especially when people are watching. We always have Cratex sticks on board.

[aquasonic]

sutterhome wrote:

Use the old points?

The majority of the time, the old points can be cleaned, polished, and reused. It takes some work, but even minor pitting can be polished away.  Even if a slight pit remains, they still work well as long as they are polished to a mirror like finish. A final dressing with 1000 grit sandpaper really shines them up.

The original OMC points with the trademark “M” seem to fit and work every time. I value them, and prefer the used ones to what’s available now. The current points on the market seem to be junk, and have no quality control. It’s a shame that even the BRP/OMC points makers have lost their quality.

Improvise-Adapt-Overcome

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