Oliver 70 starting problem

Bob M

Well-known Member
Neighbor has a restored '38(?) Oliver 70. Ran great when parked inside for the winter. However despite a new battery and fresh gas it could not be started coming out of storage last week.

First determined problem to be "no spark". Removed the mag cover and found several teaspoons of motor oil inside. Carefully cleaned it then filed, degreased and reset the points (0.013"). Replaced the cover and checked the timing with a timing light - it was off just a couple degrees, though the light didn't flash consistently.

Tried cranking again. First got a couple loud backfires out the exhaust. The engine then started, ran fine for about 2 minutes then quit. No amount of cranking could get it to fire again. We removed the kill switch wire - still could get no fire.

Put the timing light on #1 - got an occasional flash but usually nothing. However with the #1 plug removed and lying on the head it showed what looks to be a normal spark.

Did observe the mag impulse only snaps once or twice when you first hit the starter. After that the mag is silent during cranking.

I'm thinking the problem is the impulse - it's disengaging at too low an RPM causing the spark to be too weak to fire the engine.

Does this make sense, or is there something else we should be looking for??

Thanks! ....Bob M
 
Thought of that - but I get nice solid stream of gas flows when the bowl drain plug is removed.

Also it won't fire on ether sprayed into the carb air inlet.

Incidentally the plugs (D-16) are brand new...
 
it takes more juice to fire a plug under compression, so with the plug removed the mag fires it right but when plug is installed and under compression the mag might be to weak to fire it.
 

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