Distributor Insertion

PaulW_NJ · Jun 20, 2014

Finally trying to restart my 240U after rebuilding the engine, and discovered last night I had apparently put the distributor in 180 degrees out of synch with the valves. So it was firing on the #1 cylinder exhaust stroke rather than the compression (explaining the backfires but no start). OK, so I realize I need to point the rotor to #1 wire position on the distributor cap, while the #1 piston is TDC on compression. But how do I know the correct position of the distributor housing itself? While the distributor was out, I replaced the points with a Petronix electonics ignition, so I can"t watch for points opening.

Would appreciate thoughts and recommendations.

Thanks

John T · Jun 20, 2014

This may or may not be visible to your eye HOWEVER the points were replaced by a rotor that has small magnets (like high cam lobes) which pass by a tiny pick up coil which triggers the elec switch to open just as the high cam lobes opened the points.

Soooooo if those teeny magnets (rotating part) and the pickup coil location (fixed part) are visible to the eye?????????????????????????????????????????????, the spark would take place when the rotor tip is correctly pointed and the rotating magnet is just passing the pick up coil.

I doubt that's visible so likely no help but its all I got lol

Or else, have a plug wired up outside where you can see when it fires??

Or else, if a 6/12 VDC test lamp is placed on the distributors small side terminal INPUT or coils (to dist teminal) OUTPUT and the engine is rotated slowly, the spark takes place when the lite flashes ON. That's when the rotor tip aligns with the correct cap terminal,,,,the magnet passes the pickup coil,,,,,,,,plug fires.

Theres more I overlooked but have to get back to mowing before it rains

John T

Dean Olson · Jun 20, 2014

#1 piston in top dead center of compression stroke.

With distributor cap on, mark #1 location on distributor. I use a pencil so I can wipe mark off.

Take cap off and line up rotor with mark and stab it. It usually takes me a couple time as the rotor will spin at the gears mesh and be off a little. Now you can just rotate the distributor and make it work but I set all my tractors at the same distributor orientation.

pete 23 · Jun 20, 2014

I just repaired a distributor off a Farmall 300 a couple weeks ago that had electronic ignition. I just put it on top dead center mark on pulley like I do with any point system. Put dist on with rotor pointing to number one on cap. Looked at am meter when I turned switch on and saw that current was flowing through coil like normal. Took coil wire out of cap and held it a bit away from ground, turned dist against rotation until coil sparked just exactly like I do with point system. Double checked for full advance of 22 degrees at full throttle and near top dead center at low idle. Like most tractors around it didn't idle very slow so was partially advanced at lowest speed. Customer happy, good to go.

Owen Aaland · Jun 20, 2014

Looks like no one has answered your question yet. Mount the distributor so the wire coming from the distributor is at the three o'clock position when looking at it from the back.

Distributor Insertion

PaulW_NJ

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John T

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Dean Olson

Well-known Member

pete 23

Well-known Member

Owen Aaland

Well-known Member

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