How do I check if spark is good enough?

All to do with wiring, charging or just trying to figure out whats gone wrong.

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GT500-2stroke
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How do I check if spark is good enough?

Post by GT500-2stroke »

Hi experts:

First of all, thanks to all who helped me get to the point of getting the spark on spark plugs.

( When I acquired the bike, previous person had added one more wire to primary of ignition coil, for reason unknown to me.
When I removed that wire, as per the wiring diagram, and checked spark, I was able to get spark finally!)

I suspect, spark on left side is intermittent and/or weak.
Spark on the right side looks stronger and more consistent.

It could be due to kinda loose connection between spark plug cap and Ignition coil thick wire.
I am thinking of soldering a piece of wire in between, as i am not happy with quality of connection.

Anyway, my question is how should I check spark visually while kicking the bike?
I mean, the vibration from kicking makes it tough to visually detect any spark and hard to tell if it strong or not.

How do you confirm a good spark?

Any ideas?

Currently bike does not have fuel system/carbs restored, to bike is in not running state.
Just want to check quality of spark at this point in restoration before the bike is running.

Thanks.
GTandcbr
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Re: How do I check if spark is good enough?

Post by GTandcbr »

You can check visually. Shut the garage door so its dark inside. Take out the spark plug connect it to the plug cap and then lay it on the cylinder head. Kick the bike over. You should have a big fat blue spark. If the spark is weak it usually shows a yellow colour.
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GT500-2stroke
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Re: How do I check if spark is good enough?

Post by GT500-2stroke »

GTandcbr wrote:You can check visually. Shut the garage door so its dark inside. Take out the spark plug connect it to the plug cap and then lay it on the cylinder head. Kick the bike over. You should have a big fat blue spark. If the spark is weak it usually shows a yellow colour.
Thanks for tips.

Spark on my right side is blue, but I suspect I can barely see the spark on left side, as it
sparks intermittently.
I am concerned about left side, as far as I can tell.
left side spark is not a regular as on right side.

What could be causing this, and how to fix?

Also, I have some constraints, that I need work outside garage in my side yard, where the light is brighter.
I guess I need to try to see it when it is dark outside.
Any other ideas?
karl pa
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Re: How do I check if spark is good enough?

Post by karl pa »

The GT500 has one ignition coil that fires both plugs at the same time, If you have spark on one, your PEI is working, I would look at the plug cap or plug wire on the other, there is a chance the coil could be having trouble delivering spark to that wire. Are you using the same plug, if not it could just be a bad plug.
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GT500-2stroke
Around the block
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Country: USA
Suzuki 2-Strokes: GT100, GT500

Re: How do I check if spark is good enough?

Post by GT500-2stroke »

karl pa wrote:The GT500 has one ignition coil that fires both plugs at the same time, If you have spark on one, your PEI is working, I would look at the plug cap or plug wire on the other, there is a chance the coil could be having trouble delivering spark to that wire. Are you using the same plug, if not it could just be a bad plug.
Good points.

Based on your inputs:
1. Plug cap
2. Plug wire
3. Bad plug

I will work on above one by one.

I suspect the CONNECTION between plug cap and ignition coil wire is not solid enough.

Length of ignition coil wire is not generous in my case, so I feel I will just solder a piece of wire to it.
Then find a piece of connector which will thread onto plug cap.
Then solder these two.

If this does not help, will try to swap plugs to rule it out.
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Alan H
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Re: How do I check if spark is good enough?

Post by Alan H »

Just replace the HT leads for copper cored leads. They unscrew. Don't join extra bits on.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
GT500-2stroke
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Re: How do I check if spark is good enough?

Post by GT500-2stroke »

Alan H wrote:Just replace the HT leads for copper cored leads. They unscrew. Don't join extra bits on.
Oh. Ok.

Where do I buy copper cored leads?
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Alan H
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Re: How do I check if spark is good enough?

Post by Alan H »

Ebay or car shop that understands engines, not the multi national places!
https://www.ebay.co.uk/itm/7mm-Motorcyc ... SwsYpaQwH2" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

I'm sure they have the stuff at your side of the pond!

There are different colours to match paintwork or frame too. :up:
Think of how stupid the average person is, then realise that half of them are more stupid than that.
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