points spark

[nutsandbolts]

Hey all,
78 gs 750. Put new points in recently and I'm finding the 2&3 points a little weak and erratic. Compared to the 1&4 points which seem to give me a strong spark and more consistently. I double checked the gap, timing for both (full plate and half plate).
Is this a sign of condensor going bad? Any other suggestions would be helpful.
Thanks in advance

[Big T]

Could be condensor, could be coil or plug wires

Did you replace the condensors with the points?

[BIKERTUCKER]

If did not have problem before points change, new points could be a little dirty or just a film of oil. I've had good luck while engine is running ,take a business calling card (small one that fits in your wallet) make sure it's mostly white, don't want a collored one. Place it between the points as engine is running and slowly move it between point contact area. This will gently clean the points and the card will absorb any fine layer of oil.

Good luck

Tim

[rustybronco]

Hey all,
78 gs 750. Put new points in recently and I'm finding the 2&3 points a little weak and erratic. Compared to the 1&4 points which seem to give me a strong spark and more consistently.

It sounds like the condenser for 1 & 4 is bad.

[nutsandbolts]

Hey, thanks for the comments.
No, didn't change the condensers with the points. Its got new plugs though with proper gap.
I'll try that business card tip and then maybe swap the condensers around to see it that moves the problem.
Condensers easy to change?

[rustybronco]

Condensers easy to change?

Yes sir they are.

[gggGary]

there are piles of used perfectly good points and condensers clogging the landfills. The condenser wires are a 30 second swap see if your bad spark follows the condenser. Then get out your multi meter adn ohm out the coils more or less 3 to 5 ohms on the primary 10K to 15K ohms on the secondary and infinity from either primary wire to ground. If one is way out of spec there is your issue. you could also swap coils and see if the weak spark follows the coil, if so you have narrowed the issue down to coil, plug wires or sparkplug cap.

[gggGary]

Hey all,
78 gs 750. Put new points in recently and I'm finding the 2&3 points a little weak and erratic. Compared to the 1&4 points which seem to give me a strong spark and more consistently. I double checked the gap, timing for both (full plate and half plate).
Is this a sign of condensor going bad? Any other suggestions would be helpful.
Thanks in advance

I am assuming when you speak of the weak spark you are saying at the plug and not across the points?

[nutsandbolts]

good to know they're easy.
I will try ohming them.
No, I was referring to the spark at the points. 1&4 very bright, 2&3 intermittant and weak.
Yes, I do think moving the condensers to see if the issue folows is easiest.
Thanks for the comments

[gggGary]

Well then I am now in agreement that condensers is the likely culprit. What did the old points look like? The condenser serves several purposes, it stops or reduces the spark as the points open so a strong spark at the points is a sign the condenser is not working. It also helps contol the voltages in the coil so your spark plug spark on the set with a strong points spark is likely to be weaker than it should be.

[Big T]

Exactly what Gary says

There should be little or no spark at the points. Any spark at the points is taking away from spark at the coils.

IMHO, you should toss the points and go with a Dyna S. Cheaper in the long term, never mess with it again, no point or condensor problems ever.

[rustybronco]

No, I was referring to the spark at the points. 1&4 very bright,

The condenser is bad.

[rustybronco]

Kool huh? http://s612.photobucket.com/albums/t...nt=Cap0002.flv

[Big T]

Kool huh? http://s612.photobucket.com/albums/t...nt=Cap0002.flv

I think I can see the welding occurring on the 1-4 points as he revs it up!

[850 Combat]

According to the Two Stroke Tuning book by Gordon Jennings I bought 30 some years ago, when the points open, and the high tension side of the coil is released to spark, a field is generated in the low tension side of the points, which interrupts the spark. The condenser is supposed to intercept this unwanted voltage and keep the points from arcing.

It still sounds good to me.