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Discussion Starter · #1 ·
So... after finally getting my '82 GL500i back on the road, I've been slowly taking care of the malfunctions that come with running a 40 year old bike with unknown maintenance history, and... I've hit a slight bump.

The bike runs... ~90% fine. I've put a few hundred miles on it already and it hasn't croaked, which is probably more of a testament to Honda's engineers than my own developing skills. It runs a bit rougher than I feel like it should be, and I lost spark to the right cylinder the other day while cruising down the highway. It kept chugging along on one cylinder until I hit a hill, at which time I shifted down to fourth and revved the engine... and then spark came back and it's been... adequate... since then.

I could be wrong, but I feel like after replacing the alternator, battery, and timing system, the only things left are the coils and plugs. I haven't gotten around to checking resistances on the coils, but... that's not what actually brought me here.

My Haynes manual recommends NGK DR8ES-L plugs for my model, and that's what I've been using since I first got the bike. The thing is... my spark plug caps still have their resistors. MotoFaction recommends DR8ES-L plugs for spark plug caps without resistors.

The bike runs, obviously. But my knowledge and experience with ignition systems is... rudimentary, so I wanted to get a second opinion with more experience before I start buying more parts.

How bad is it that I'm running resistor plugs with resistor caps? Irrelevant? 'I'm torturing my coils every time I run the engine'?


Also, while we're on the subject, has anyone else completely replaced a TI ignition system with aftermarket parts? Is it better/ worse, or can't tell the difference?

Better yet, has anyone put a few tens of thousands of miles on aftermarket ignitions? I intend to keep putting miles on this bike, and I'd rather not be replacing coils and spark plugs at the same time.


Any wisdom is appreciated. Thanks in advance,
Sam
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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By the end of this model series, Honda was specifying resistor plugs with resistor caps.
I do suspect you have caps with excessively high resistance. Best to check those.
 

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Discussion Starter · #3 ·
Well, one of the caps is perfectly within spec.
The other one is... dead. The spring, rod, and resistor are all fine, but it has no continuity otherwise. The fault seems to be inside the elbow.
 

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The cap may be corroded inside. I've filled them with white vinegar and then let it set for a while. With a sharpened rod, not too sharp, I've lightly scraped the inside and that got rid of the corrosion. might try that.
 

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Spark plugs with resistors in are perfectly fine to use with caps with resistors in.

I had a similar problem once than you experience with your measurements in one of the cap. For a short while (though neither cylinder failed completely), I had a bit of a lumpy idle and the bike wasn't the best at low speed running. Specifically when cold the bike would mis-fire and be quite reluctant and unhappy (got better when warmed up a bit).

One of the spark plug caps measured 65k ohms resistence when I got around to checking. The internal resistor seemed to have got rusty connections either side of it. I took the cap apart and simply cleaned the replaced the resistor (cleaning that up did nothing to the resistence) and each component in the cap and put it back together, and measuring it was back down to 5k. Bike was happy as larry after that.
 

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Discussion Starter · #7 · (Edited)
My internet's being a butt! 🤬 Can't even finish replying...

Have you trimmed back a bit of wire on the HT wire? My son's bike also had a broken elbow connection. had to get a new cap. Believe DSS has them?
I unscrewed the caps completely for testing. I'll check the leads when I pull the coils for testing.

The cap may be corroded inside. I've filled them with white vinegar and then let it set for a while. With a sharpened rod, not too sharp, I've lightly scraped the inside and that got rid of the corrosion. might try that.
Vinegar applied. Can't hurt, I suppose...

One of the spark plug caps measured 65k ohms resistence when I got around to checking. The internal resistor seemed to have got rusty connections either side of it. I took the cap apart and simply cleaned the replaced the resistor (cleaning that up did nothing to the resistence) and each component in the cap and put it back together, and measuring it was back down to 5k. Bike was happy as larry after that.
Mine has infinite resistance. No circuit at all.


Thanks for the suggestions anyway, everyone. I'll try the vinegar (because why not) but it's not looking good. I'll search for replacements in the meantime, assuming my internet doesn't crap itself...

Edit:
Huh... a few hours in the vinegar, and there's continuity again. No telling how long that will last, so I still have new caps on the way, but if it works for a few hundred miles, I'll be happy.

I'll see about pulling the coils later this week and update the thread again.
 

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Discussion Starter · #9 ·
Update/Bump (Bumpdate?)

Internet's been a real butt lately, and, well, let's just say life happened.

Anywho...

I went ahead and grabbed a pair of new aftermarket plug caps from DSS. Seems to be idling a bit smoother but... didn't solve my initial problem. Just last Sunday, the right cylinder cut out about 40 minutes into the ride. Made it into town on one cylinder, and... it was fine the rest of the day.

Electrical problems are fun.

So... about my original question regarding aftermarket coils.

Also, while we're on the subject, has anyone else completely replaced a TI ignition system with aftermarket parts? Is it better/ worse, or can't tell the difference?

Better yet, has anyone put a few tens of thousands of miles on aftermarket ignitions? I intend to keep putting miles on this bike, and I'd rather not be replacing coils and spark plugs at the same time.
There's a few options linked on MotoFaction (one of the links is broken...), but does anyone have real-world experience with them? Or am I destined to be my own cartographer here?
 

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I have a GL700 {650}in the shed running a raesan. It works well.

I have also fitted a number of the systems to CDI bikes.

Both raesan systems are quite similar.
 

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No need to trouble yourself with fitting anything other than the original TI ignition system which (normally) is completely reliable and very easy to troubleshoot.
How do you know that you are losing spark on one side - how are you checking this?
Have you checked the resistances of the pulser coils when the problem arises?
Blue/blue and yellow/yellow multiplug under the seat.
It has been known before now that they can go open circuit or out of spec when the engine is hot.
Spec is 530 +/- 30 ohms.
You could also swap over the ignitors and see if the problem switches to the other cylinder, coils too if necessary.
 

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Discussion Starter · #12 ·
No need to trouble yourself with fitting anything other than the original TI ignition system which (normally) is completely reliable and very easy to troubleshoot.
How do you know that you are losing spark on one side - how are you checking this?
Have you checked the resistances of the pulser coils when the problem arises?
Blue/blue and yellow/yellow multiplug under the seat.
It has been known before now that they can go open circuit or out of spec when the engine is hot.
Spec is 530 +/- 30 ohms.
You could also swap over the ignitors and see if the problem switches to the other cylinder, coils too if necessary.
Refer here and here. I've already found the pulser coils to be faulty and replaced them with a Rae-San system.

I also just replaced the plug caps after finding one of them to be faulty, and just before that, I replaced the battery, stator, and spark plugs.

Since this problem is infrequent and intermittent, I don't have many opportunities to test, and when I do, I'm on the road. Simply put, I reached down and pulled the left plug cap, and the engine lost power completely. I can smell fuel and hear backfiring, so there is fuel in the cylinder. Ignition then.

So, process of elimination. Battery is fine. Stator is fine. Ergo, the system is powered.
Fuel cap is fine. Fuel line is fine. Carbs are fine. Valves are fine. Compression is fine. The system is fueled.
Rae-San is fine. Plug caps are fine. Plugs are fine. That leaves the plug leads and the coils.

I'm playing a game of 'hope for the best and prepare for the worst', with the best being the leads and the worst being the coils. In the latter case, I want to be prepared and educated before the problem becomes more permanent and I'm left sitting around waiting for answers and parts with no personal transportation.

In addition, there seems to be a dearth of information regarding aftermarket ignition components out there, especially regarding TAI systems. Correct me if I'm wrong. I understand that the TAI system is regarded as 'very reliable', but that is supremely unhelpful to someone who is actively experiencing problems. As these bikes age, parts will wear out. If nothing else, I hope this thread helps any future members who have similar questions.

Anyway...
I hope this didn't come across as too ranty/passive-agressive. No salt is intended.🙂 I can be a little... blunt, or so I'm told.

I also should really get off my buns and do some testing...

Cheers!
Sam
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Since the HT leads are replaceable on the GL, that would be an easy, relatively inexpensive step to take.
Also, as suggested, swap the coils right to left, and see where the fault occurs next time. If it moves with the coil, that will definitively identify the culprit.
 

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I had similar problems with my TAI EC 500. Coils checked out ok and new leads, non resistor plugs and a very careful cleaning of the plug caps to ensure continuity through the spring, resistor and end screw fixed things.
 

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Discussion Starter · #16 ·
So...

After a week of tweaking and tinkering and wishing I had internet access, I've discovered my real problem. Turns out, it wasn't anything mentioned above.

The left cylinder has an internal oil leak. Bike doesn't run so well on oil.

Regardless, since my original question about coils hasn't seen any replies, I'll be leaving this thread. Might start a new one if I get in over my head.

Thank you all for the suggestions and advice anyway,
Sam
 
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