JD 50 - no fire

[GEJD6]

New to me JD 50, will not try to fire. Ended up filling crankcase with gas I assume due to flooding from trying to start and dirty carb. Going to rebuild carb but how do I troubleshoot ignition side? It is 12v negative ground, put new plugs, wires, points and condenser along with new distributor cap. Spark is weak and intermittent at the points, is this sign of faulty coil?

 

[ET]

The most likely reason your crankcase is full of gas is the diaphragms in the fuel shutoff on the sediment bowel are leaking.

 

[Fixingfarmer]

With no carb installed this is a perfect time to test the ignition first put a little ether in the intake and try starting the tractor once. Don't use too much of it you just want to see if it pops or backfires or anything at all. With the carb off you eliminate the flooding. If it takes right off like it wants to start carb issue.

Be sure the shutoff valve works when you are done and use it every time you shut the tractor off.

Check that you have the correct wire going each cylinder. Top wire should go to the left side (flywheel or drivers side if it was a car) if everything is timed right.

Check that your coil is hooked up correctly. Ignition wire to + since its - ground 12v coil should be 3 ohms of resistance between + and - if not there should be a resistor nearby

from ignition wire source to that - terminal in coil with wire headed to distributor there should be 3 ohms resistance with your meter that is what counts. Its possible there will be a nice delco part number with raised numbers on the side of the coil yet to tell you what the plan was if you go looking for a new one.

 

[Deere Mark]

New to me JD 50, will not try to fire. Ended up filling crankcase with gas I assume due to flooding from trying to start and dirty carb. Going to rebuild carb but how do I troubleshoot ignition side? It is 12v negative ground, put new plugs, wires, points and condenser along with new distributor cap. Spark is weak and intermittent at the points, is this sign of faulty coil?

Check for good spark at the plugs. Get a spark tester if necessary. A small amount of spark at the points is normal.

 

[620 John]

I've had a condenser bad right out of the box. If you have a spare condenser I'd try that first

 

[Kansas rhody]

From a fellow 50 owner, if you put in new points try cleaning them up some, a bit of emery paper or maybe 220 grit sandpaper, they might have a film on them right out of the box. The sediment bowls are notoriously for leaking over time, I have put in a shutoff valve between the bowl and the carb on my tractors, let us know what what you find out, good luck

 

[wore out]

From a fellow 50 owner, if you put in new points try cleaning them up some, a bit of emery paper or maybe 220 grit sandpaper, they might have a film on them right out of the box. The sediment bowls are notoriously for leaking over time, I have put in a shutoff valve between the bowl and the carb on my tractors, let us know what what you find out, good luck

Sandpaper or emery paper is RUINATION to new points, once the smooth factory finish is scratched up they can become "addicted" to having to be sanded again and again.

I suggest using electrical contact cleaner spray followed by a good burnishing with clean white paper "cardstock", followed by another spray of contact cleaner (with the points "open") to remove any fuzz and residue. Allow to "air dry" before cranking engine.

Doing that will get rid of any non-conductive residue or oxide without scratching them to #&$$.

 

[JIM MN]

Why is it negative ground? Does it have an alternator? Clean those new points. They have a film on them. Contact cleaner and wipe with a clean white business card until it pulls through clean.

 

[Rich'sToys]

Why is it negative ground? Does it have an alternator?

I wondered about that too. They were originally positive ground from the factory.

 

[Kansas rhody]

Thanks for the heads up on using sandpaper on my points, never thought it would make a big difference. I’m putting in some new ones this spring and will try the card stock method

 

[Fixingfarmer]

I’ve had better luck with the auto parts store points and condensers (napa in my case). Haven’t had to shine the last three sets I put in up the Deere ones it seemed like every time they wouldn’t fire right away I’m not sure why I assume there’s more classic cars and more turnover of the stock

 

[DonB]

I clean my new points with liquor thinner. I don't want to scratch them.

 

[GEJD60]

Why is it negative ground? Does it have an alternator? Clean those new points. They have a film on them. Contact cleaner and wipe with a clean white business card until it pulls through clean.

it has been converted at some point as it does have an altenator hanging off the side...

 

[GEJD60]

With no carb installed this is a perfect time to test the ignition first put a little ether in the intake and try starting the tractor once. Don't use too much of it you just want to see if it pops or backfires or anything at all. With the carb off you eliminate the flooding. If it takes right off like it wants to start carb issue.

Be sure the shutoff valve works when you are done and use it every time you shut the tractor off.

Check that you have the correct wire going each cylinder. Top wire should go to the left side (flywheel or drivers side if it was a car) if everything is timed right.

Check that your coil is hooked up correctly. Ignition wire to + since its - ground 12v coil should be 3 ohms of resistance between + and - if not there should be a resistor nearby

from ignition wire source to that - terminal in coil with wire headed to distributor there should be 3 ohms resistance with your meter that is what counts. Its possible there will be a nice delco part number with raised numbers on the side of the coil yet to tell you what the plan was if you go looking for a new one.

thank you for this, will give it a shot this weekend when I get back to it.