misfiring

[pisten-bully]

Thanks Jason, you and Dave have the same idea! I only hesitated on replacing the condenser because I think a bad condenser will give you burnt points, and my points are fine. But I've got one and if it ever stops raining here I'll give it a shot!

[Skirted]

New condensers are cheaply made (yes even NAPA I've cut them open) and aren't made to withstand the vibration on our bikes. I'd try changing it for sure especially since you've been over everything else and know your bike well.
I know I'm not the only one who went about troubleshooting everything else bypassing a bad condenser because it was "new".

[T. Cotten]

Cotten, it’s always good to ask as a reminder, thanks!

I’ve always thought the weak link was the gasket between the manifold and carburetor, it’s a pretty chubby gasket but the screws don’t bite very deep into the brass carburetor!

BTW, the non-Liberty float was rubbing on the bowl, probably from swelling, so I merely tweaked it sideways. The level was good (...and still good today).

Personally, Harry,..

I think 'chubby' can be a problem: The more squish, the more the flanges can distort. (So I commissioned skinny ones...)
Since this interface cannot be bubble-tested, we must arbitrarily grind the manifold's flange to flat for inspection,
and lathe-cut the carb flange to flat.

99.9% need it.
Then a torque to 10, no more than 13 ft-lbs should do it; But if problems persist, a test at idle with an un-lit propane torch can display an issue, although it cannot discern between the flanges and the throttle bushings.

Do you think the float will stop swelling?
'Spose it could. Its about the gas and not the float.

...Cotten
PS: Note in the attachment how the region of the flange adjacent to the casting-stiffening gallery holds it from being 'pulled' by the fastener stress.

[pisten-bully]

Cotten, it’s always good to ask as a reminder, thanks!

I’ve always thought the weak link was the gasket between the manifold and carburetor, it’s a pretty chubby gasket but the screws don’t bite very deep into the brass carburetor!

BTW, the non-Liberty float was rubbing on the bowl, probably from swelling, so I merely tweaked it sideways. The level was good (...and still good today).

[T. Cotten]

Passed the bubble test, and I was kinda hoping it wouldn’t!

Sorry, but I always gotta ask, Harry,...

You bubbletested with the carb off, at a full 15 psi, with a constant, regulated air supply?

False negatives are more agony than a positive!

With a really evil gremlin, sometimes you have to turn the motor until intakes open, bump the pressure, and then test the headgaskets, sparkplugs, etc.
(Its a bit normal to come out of valve covers..)

….Cotten
PS: In your very first post, you mentioned re-setting the float. Had it changed?
PPS: Were the Maytag rotors and caps the evil ones, Folks? (Asking for a friend.)

[pisten-bully]

Passed the bubble test, and I was kinda hoping it wouldn’t!

[pisten-bully]

Thanks you guys! I need to find a problem and it’s tough when it’s intermittent. Harness tests good for continuity, battery to ammeter, ammeter to switch, battery to switch, switch to coil, coil to distributor. Coil and condenser are 2000 miles new and I’ve got good spark. Only thing I’ve found so far is valve lash on the rear had no gap on either valve, front was fine. Timing is good, points good. Replaced the inline circuit breaker.

I’m going for a bubble test next.

[Tom Wilcock]

Check to see that your ignition switch does not have a bad contact. I once found a bad splice in a new wiring harness where the battery+ wire is connected to the stop light switch wire. The connection is near the rear of the gas tank and seat post area. A friend also found a ban connection in that wire on his bike.
Tom

[indian301]

Misfiring

It couldn’t even sustain an idle without misfiring! I stopped once and changed out the cap and rotor, that effort gave me another 10 minutes (tops) without a misfire.

Harry,
I think I would change the condenser first. Then if that does not fix it change the ignition coil.



Dave

[pisten-bully]

Bah! I got 90 miles away and it started missing again. At first just an occasional misfire, but the frequency slowly increased to the point where it was time to call it quits, 30 miles from home. It couldn’t even sustain an idle without misfiring! I stopped once and changed out the cap and rotor, that effort gave me another 10 minutes (tops) without a misfire.

Funny thing, in Vermont there are many locations without cell service, so I was at a general store using their phone to call my wife for a rescue. She didn’t recognize the number showing up on her phone because it was the general store’s number, and she had received an annoying robo call earlier...so she blocked my calls! All’s well that ends well, but I spent 3 hours trying to reach her...at least I was next to a river in the shade!

The hunt continues! Jason, I think the rotors were somehow made wrong because I’ve been using older rotors and none of them have broken!

[Skirted]

How'd the trusty Chief do yesterday Harry? And by the way, what did you ever determine the cause was for the broken rotor a while back? Defective part?

[pisten-bully]

I’ve got no answer! Could’ve been gas, or it could’ve been distributor cap and rotor, those are the only two areas I addressed. All I know is today I had time for 40 miles and it ran great, zero misfires. About 20 miles on the main tank, 20 miles on reserve....but I had new gas in both tanks. And I cleaned the distributor cap posts and rotor....that’s all I did. So bad gas or bad ignition in the distributor.

Tomorrow I’ll put 200 miles +/- on, I trust the Chief again!

[exeric]

As much as you ride your Chief, I know you will find the problem soon, Harry. It's the bikes that don't get out much that are so difficult to diagnose.

[pisten-bully]

Oh, and thanks Eric, I’m hoping it’s as easy as bad gas! (...that is not a joke about Taco Bell!)

[pisten-bully]

I would check the charging system.

Thanks Dave, that's interesting to think about! I pack along a small voltmeter and when it quit I found something like .7 volts when I grounded the meter to the motor and the other probe to the positive terminal of the battery, and when I next tested on both battery terminals I got 12.5+ volts and that led me to the ground wire. Indian Frank set me up with an electronic regulator about 10 years ago and it's been bullet proof and trouble free. I also have an auto reset breaker in line off the positive post of the battery, and the thought crossed my mind that the circuit breaker may be failing. And like Tomfiii suggests I'll check it all over before I venture too far away!

It just seemed like the bad gas theory is logical because my misfiring didn't start until I switched to reserve, and I rarely go much more than 10 or 15 miles on reserve before stopping for gas...so some of that gas has been in there all summer! Too easy?