VL acts like it's running out of gas....but

[frichie68]

35 VLD sputters and dies like it's out of gas, usually while cruising at 45-55. Closing the choke briefly usually causes it to sputter back to life (coincidence or fluke?) and run fine for another 2 to 5 miles before repeating. This occurs regardless of which tank is turned on, main or reserve. Possibly heat related as it starts and runs fine for the first 8-10 miles.
This is what I've done so far:
Checked, cleaned adjusted points.
Replaced the condenser.
Tanks recently rebuilt (1000 miles ago), RE-checked for floaters and debris, none found, filter and gas lines blown out, nothing found.
Carb disassembled and cleaned, no debris found.-Cork float was blistered on one side(modern gas?), sanded smooth and recoated with model airplane dope.....no change.
I've read several "How to test coil" articles but I'm short on electrics, didn't understand most of it. It looks like I'm getting 1.8 ohms between the + and - terminals, no reading at all from either terminal to either plug wire, meter set at all positions. No reading from either terminal to ground.
This bike has always been a 1-2 kick starter, usually leaning on the side stand. It will sit and idle like a tractor forever parked on either stand.
Nothing I've done has had any effect.
ANY suggestions would be much appreciated.

[Rubone]

Are the tank vents (gas caps) clear?

[Jim]

Just so you know Rich, I had checked my coil when it was brand new (Repop) and the coil ohm reading across the terminals is 1.5 OHMS. This is without any wires hooked up to it. Hope that clears that question up for you. According to a "Buick" website I found, for a 6V coil it should fall between 1.4 and 1.6 ohms.

Good Idea what Rubone said about checking the VENT holes in your gas caps. Blow air through bottom hole and you should have it exit near the top.

[frichie68]

Are the tank vents (gas caps) clear?

Yes, should have mentioned that. Also plugs are a nice coffee-with-cream color indicating mix is close, no difference between the two.

[frichie68]

Just so you know Rich, I had checked my coil when it was brand new (Repop) and the coil ohm reading across the terminals is 1.5 OHMS. This is without any wires hooked up to it. Hope that clears that question up for you. According to a "Buick" website I found, for a 6V coil it should fall between 1.4 and 1.6 ohms.

Good Idea what Rubone said about checking the VENT holes in your gas caps. Blow air through bottom hole and you should have it exit near the top.

Thanks Jim, that "C" word has been going thru my head.

[jwl]

I had a similar problem and found that raising the float level cured my problem. No idea if it would help you or not. Good Luck!!

[Shaky Jake]

You could be onto something with the coil. I've had coils that work when they're cold and quit working when they warm up. Not sure if you tested it cold or warm.

Kevin

.

[Steve Slocombe]

I'd also check the tank cap vents, and make sure you're not using leather washers under the caps. Tank sealers can also block or restrict the built-in gas filters in the tanks, so break these out if necessary. Repro coils seem to have smaller holes for the spark plug cables, so push these down tight. The spark cable ends also need to be cut back about a quarter inch and the inner wires turned over to ensure good contact in the coil. My bikes run more chocolate brown to black on the rear plug and grey to brown on the front, so you might be running a shade lean. As always, pull the manifold nuts up tight after the engine is well heated. Condenser is always worth checking, and that little cardboard washer under the circuit breaker post to make sure it is not occasionally grounding. I wouldn't run a cork float these days as they don't last a season with all the alcohol in modern gas. Let us know what fixes it for you.

[frichie68]

You could be onto something with the coil. I've had coils that work when they're cold and quit working when they warm up. Not sure if you tested it cold or warm.

Kevin

.

Re-checked ohms last night when it cooled: 1.7. 10 mile ride this morning, measured again hot, went to 2.0. I don't know enough about 'lectrics and/or coils to know if this means anything or not.

[Shaky Jake]

Re-checked ohms last night when it cooled: 1.7. 10 mile ride this morning, measured again hot, went to 2.0. I don't know enough about 'lectrics and/or coils to know if this means anything or not.

I don't know much about them either Rich. I don't feel like 2.0 ohms would be high enough to keep it from running, but maybe someone else can say. I think what you'd have to do is check it right after the bike died and see if it goes way high, like almost infinity. Either that or try a different coil, if you can get your hands on one, and see if the problem goes away.

Kevin

.

[frichie68]

Next question: Is it "normal" for a coil to change resistance with temperature changes?
I'm down to one bike or I'd go crank up another one and check ohms cold and hot.

[frichie68]

Ithat little cardboard washer under the circuit breaker post to make sure it is not occasionally grounding.

????

I don't see anything like that, please explain further.

[Steve Slocombe]

Dear Rich, it is Harley part 1617-30 LT stud insulator, and you can see it in the exploded diagram on page 12-4 of the latest edition of my VL book. It goes underneath the circuit breaker spool, and insulates the terminal soldered to the breaker/coil wire from that spool. When say changing points you can turn the terminal when tightening up the nuts and ground the terminal against the spool, thus stopping the sparks. It is also conceivable that a deteriorated insulator could cause intermittent grounding as the advance/retard spiral is twisted. I've also had replica points touch a contact plate screw when fully open on one timer cam lobe, but not the other, so causing running on one cylinder. That was a tough one to chase down.

[frichie68]

Dear Rich, it is Harley part 1617-30 LT stud insulator, and you can see it in the exploded diagram on page 12-4 of the latest edition of my VL book. It goes underneath the circuit breaker spool, and insulates the terminal soldered to the breaker/coil wire from that spool. When say changing points you can turn the terminal when tightening up the nuts and ground the terminal against the spool, thus stopping the sparks. It is also conceivable that a deteriorated insulator could cause intermittent grounding as the advance/retard spiral is twisted. I've also had replica points touch a contact plate screw when fully open on one timer cam lobe, but not the other, so causing running on one cylinder. That was a tough one to chase down.

Sounds simple and basic but...I don't have your LATEST edition and was unable to find a photo on the web. I have a new set of (unused) points, don't see anything like that in the package. I could install them but if the insulator is missing, it could still be wrong and end up with the same problem. I could probably make the insulator but without a picture, I'm not sure where it goes.
Also, still trying to determine if it's normal for the coil to change resistance when hot.

[wideglide38]

[/B]Also, still trying to determine if it's normal for the coil to change resistance when hot.

Yes, resistance rises with heat. Sounds like Steve is onto something with the stud insulator!

Regarding ignition coils, they are typically rugged and reliable; but can fail for a variety of reasons. Heat & vibration can damage the coil’s windings and insulation causing shorts in the primary or secondary windings. The number one killer of ignition coils is voltage overload caused by bad spark plugs or plug wires.

If a plug or plug wire is open or has excessive resistance, the ignition coil's output voltage can rise to the point where it burns through the coil's internal insulation causing a short. The insulation in many coils can be damaged if output exceeds 35k volts. Once this happens, the coil's output voltage may drop causing ignition misfire when the engine is under load, or the coil may cease to put out any voltage preventing the engine from starting or running.

If a coil has battery voltage at its positive terminal and is being grounded on and off in the circuit but is not producing a spark, the coil is defective and needs to be replaced.