My new ignition issue

[shotgunjoe]

Some of you will remember that I just fixed my dumb mistake on the advance assembly, I have a new issue now, and would like some opinions.

At higher rpms the bike is now cutting out, whereas before it ran strong up to redline. The very last time I rode it before the problem with the advance assembly, it ran great. I can actually hear what sounds like arcing from under the tank or something. Can't pin point the sound cause it only happens when underload at higher rpms. I tried insulating the wire assuming it might be them, and no change, it may have even gotten worse.

Tested coils again and got different results...
Both are reading 4.5ohms and 18k ohms at cap. So it seems to me that things are in order.

 

[shotgunjoe]

Nevemind... its just plain time for a pamco. Simple as that. Points are great when they are working correctly, they are a pain in the ass when not.

Also another lesson learned. Ebay filters are pure garbage... avoid avoid avoid. The rubber was actually falling apart right out of the box. After a couple laps around the block, they were ready for the trash.

 

[sgallaty]

Share it with us

 

[shotgunjoe]

Share what?

 

[sgallaty]

if you found the problem, I'm curious to know what it was.

 

[shotgunjoe]

I havent pinpointed the problem, only narrowed it down to being one of the points. One of them appears bent, and the rub block has abnormal wear. I have another set of points I put in last night, but havent tested it yet.

I will be going pamco soon either way.

 

[sgallaty]

I certainly agree that when points are working, they work reasonably well but when any one of the many tolerances are not right, they can be somewhat hard to diagnose unless one is very familiar with them. Some of the symptoms are really complex or unclear.

Because of the nature of how points work, I've seen people try to improve them and not realizing they were having a destructive effect - such as filing them, and then creating uneven surfaces etc.

I've seen a condenser go bad and cause pitting (where there was none before), that caused bad contact later after the condenser was replaced - so you end up with multiple problems that overlap.

The condenser is a capacitor that helps to prevent sparking when the points separate. If that goes bad, the arcing at the points causes the magnetic field to collapse slowly which makes the output become a weak spark that happens over a longer period of time (or not at all)

Add to that that the real measure of the points being effective is dwell (how long they are closed before they finally open to create a spark, but most manuals don't mention this -

it really is a wonder people get those things working at all.

 

[shotgunjoe]

Well I went and tested the bike, the newer points I installed are working great. Which has revealed another problem! I believe it was caused by all the backfiring from when the advance assembly came loose. The carbs aren't right... I can't explain it exactly, but its not smooth anymore, and its running really rich all of a sudden. To be honest, its been smoking for a bit now, and I assumed that the headgasket issue had resurfaced, the smell and color do not indicate oil burning though.

When it rains it pours...

I'll get back to it. Just not now, losing motivation here.

 

[sgallaty]

What color smoke?

 

[shotgunjoe]

Grey, smells like gas too.

My lack of motivation, as well as my lack of funds for a pamco, became a motivational tool in and of itself.

Thanks to a writeup by MrRiggs, I decided to disassemble a NOS Datsun distributor that I had sitting on my shelf for the past year and a half.

Heres what I came up with.

Can you see where I'm going with this? It won't fit under the original cover, but if I make the cover 10mm wider, it will.