F-me, bike quit running

[shotgunjoe]

So I take the bike out, fire it up, idling to warm up. Then pull off, its running great as it has been... half a block from my house the damn thing dies suddenly and won't refire. I push it home for diagnosing.

I have checked for fuel delivery issues, there doesn't seem to be any.
I checked for spark and get a strong blue spark on one side, and orangish spark on the other... great I'm thinking easy fix. It has been shooting flames from the exhaust every couple kicks or so... but not running.
I replaced the condensers, only to have no change. I haven't checked the color of the spark yet, and the coils OHM out at 2.0 on one side and 4.4 on the other side. Weird thing is the side with 2ohms has strong spark, and and side with 4.4ohms has the weak spark.

Could the points gap cause this?

 

[retiredgentleman]

The coil with 2 ohms will burn the points due to the high current flow. You'll have to replace that coil.

 

[shotgunjoe]

Thanks for the tip RG.

I forgot to mention that I also replaced the spark plugs.

 

[shotgunjoe]

Sanded points and set points gap to .012", still doesn't fire... Its gotta be the coils... right?

 

[sgallaty]

Start at the beginning.
Compression, spark, fuel, timing.

 

[retiredgentleman]

shotgunjoe;

I have to ask you........................how old are those coils? If they are 31 years or older, they are just plain worn out. Even when new they only put out 10k to 13k volts, but now that they are aged, they probably put out less than the rated voltage.

I recommend you up grade your ignition. Replace the points with a Pamco and get a new single, dual output coil. Get new spark plug wires as well. These bikes thrive on a hot spark.

When I first went to look at my bike at the PO's house, I asked him to start it. It had the original stock coils that were 29 years old at the time. He tried several times, having much difficulty, but eventually got it running. It ran poorly once started. One of the first things I did was to install an Accel dual output coil (30k volts). The difference was like night and day..................the bike started instantly and ran smoothly. I ran the Accel coil with points for 1 year and then switched over to a Pamco to eliminate the fiddling that goes with points.

Here's a pic of the type of spark you want for your bike.

 

[shotgunjoe]

I don't know the age of the coils honestly. However, the bike has always started easily, and today was no different. It started and ran just as it always does... and it was running very well. I was accelerating in 1st gear at about 10mph, when it bogged as if out of gas, I tried rocking the throttle to keep it running but this only made it bog worse.

This is quite the puzzler... I really need this thing running. I am selling it to get my other bikes on the road. I have 2 other XS650's. I was actually on my way to show the darn thing. She just decided she didn't want to leave.

 

[hmusket]

Have you tested the battery and charging system?

 

[jay760]

Might be worth checking the advance unit, it might have come undone enough for the timing to move,

 

[shotgunjoe]

Might be worth checking the advance unit, it might have come undone enough for the timing to move,

Hell..........

You sir, are a genius. After reading this post I remembered that I was just working on the advance assembly, and forgot to tighten it down.

Can anyone tell me what the width and length the pin is that drive the whole advance assembly is?

 

[sgallaty]

Hell..........

You sir, are a genius. After reading this post I remembered that I was just working on the advance assembly, and forgot to tighten it down.

Can anyone tell me what the width and length the pin is that drive the whole advance assembly is?

Again, and it's worth reiterating.

Assume nothing, start from the beginning.

 

[shotgunjoe]

Nevermind... found a pin same diameter and 1inch long, cut it down and she roars again!

YAY! Thanks Jay, I just needed that reminder. I feel like a dumbass, but I am happy it all worked out.