weak spark-culprit?

Brought her in to replace radiator and deal with the weak spark/hard start issue i've been experiencing. Replaced points, fully charged battery, replaced switch, cleaned all battery terminals and ground on block. Cleaned plugs (they are not old but were sooty). Now the spark will jump 3/16 on 1st revolution but will not on subsequent revolutions. Does this sound like a leaking condenser (capacitor)? How do I get a 1/4 spark everytime. I am using a storebought spark tester that is adjustable and when i close to 1/8 i get spark but it does not seem to be a blue streak overhand yellow hammer, it's seems kind of puny. I need a self-appointed sparkie-meister!

Bob, We need to know what it is you are working on.

dizzy shaft have wear / play?

are points arcing and pitting and burning? ( with correct gap? ). if points burn with correct gap, then I would check condensor.

You usually get 2 fail modes on condensors. short or open. Short means no spark period as the points are electrically closed.. Open means the poitns burn quickly.

you can have inbetween with heat or run time.. but easy to to test with an ohm meter.

Sorry fella's. I'm working on a 1949 8N front mount.

Check the condition of the ballast resistor on back of the dash. Make sure the connections are clean and tight and the resistor has no partially broken coils. Measure OHMs with all wires disconnected.

(quoted from post at 11:14:14 09/28/15) Sorry fella's. I'm working on a 1949 8N front mount.

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o, let me get this straight.....first revolution yields two good sparks, but next revolution yields two sorry sparks? Then after some indeterminate time you can again obtain two good followed by two or more bad?

Bob.........sooty plugs, eh? Guess what? yer carbie needs adjusting. Set the down-pointing mainjet to 2-turns and LEAVITT!!!.......adjust the side-pointing idlemix for FASTEST idle, NOT SMOOTHEST idle. Understand the difference? Usually, the side-pointing idlemix is 1/8-1/4 turn. As a general rule, yer 4-nipple front mount dizzy points are best adjusted on the kitchen table. Just un-snapple yer capple and un-bolt the 2-screws and walk. Adjust the points to 0.015" and POLISH the invisible CORROSION from between the points. Me? I clamp the corner of $1-bill (cheap) between the points and pull. Iff'n yer really cheap, tear a strip from HEAVY brown paper grocery sack and use that. FYI, we recommend AutoLite 437's gapped 0.025". Installation is a reversal of the removal ...except... finger install the 2-bolts and install the rotor. Now rotate the rotor until the OFF-SET tang fits the OFF-SET slot in front of camshaft. Now tighten the 2-bolts and re-snapple yer capple. Simple, eh? The 2-bolt scheme means you cannot install outta time. Iff'n you think you gotta BAD condenser, they go BAD in less than 5-mins. Even NEW condenser can be BAD rite outta the box. And surprizingly enuff, condensers seldom go bad during use, you start missin' its generally yer points. ........HTH, Dell, yer self-pointed sparkie-meister

Not exactly. 1st revolution gives a spark I would not describe as blue-streak and only jumps 3/16. 2nd revolution does not spark at all. Closing tester to 1/8 inch allows spark but once again, it's not a spark to brag about. I will replace my inadequate battery cables tonight and see what happens. I have seven condenser/capacitor's in a drawer I will start trying to see if the old girl will respond but the condenser that is currently installed is only a few months old. I also have a new terminal/resistor on another project tractor I can swap. The current resistor is original and is older than I am.
Thanks JMOR

(quoted from post at 09:44:47 09/29/15) Not exactly. 1st revolution gives a spark I would not describe as blue-streak and only jumps 3/16. 2nd revolution does not spark at all. Closing tester to 1/8 inch allows spark but once again, it's not a spark to brag about. I will replace my inadequate battery cables tonight and see what happens. I have seven condenser/capacitor's in a drawer I will start trying to see if the old girl will respond but the condenser that is currently installed is only a few months old. I also have a new terminal/resistor on another project tractor I can swap. The current resistor is original and is older than I am.
Thanks JMOR

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would verify point gap, then start changing condensers, next. Too close or too wide a gap will kill spark.

You were right on it old. After changing cables, condenser, cleaning points with dollar bill, swapping coils with another on hand, still got weak spark. Hooked up separate battery to spin engine and spark improved greatly. Seems like something in starter is drawing too many amps and that affected my spark. This may also explain why the engine turns over so slow when hot. I will look into rebuilding my starter soon but for now the little N is out of the garage and running. Thanks to you and all the other's that shared their much appreciated advice.
Bob

Always happy to help if and when I can. I have a small problem and I sure wish I can find a picture of how things fit. LOL I am trying to put my Geo Tracker back together and have 3 parts I am not sure where they fit under the dash LOL

uh, John?.........you write "resistor has no partially broken coils".......you do realize a broken coil will be an OPEN CIRCUIT and NO electrons are gonna jump the gap. You will NEVER gitt enny sparkies with a broken coil. Yeah, the "infamous" ballast resistor confuses many shade tree mechanics ...but... electrons are electrons and resistors either work or they don't. (ie...open circuit).......sparkie-meister Dell