Solid Core Plug Wires

[TxGSrider]

Ive got a couple bad plug wires and need to replace them. Right now it has Accel coils and Accel 10.5 RFI suppression wires without resistor caps but a couple are showing over 10 ohms resistance (one over 12 ohms).
I want to replace them with some solid core wires. Can I run them without resistor caps or will it mess with my CDI (or other electronics)?

 

[Nessism]

Don't think it will hurt anything. You might want to switch to resistor plugs during the next change though.

 

[Gorminrider]

They apparently make several types of coils for motorcycles- You haven't given much information but I would have the same "reactance" that Accel says you should have for the setup you have....If your "accel" coils came with 10-12 KILO-OHM leads, you should have 10k ohm caps.

But again, I would refer to Accel.

 

[Steve]

Nothing is going to mess with your CDI, mainly because you don't have one.

You DO have an electronic ignition module that Suzuki calls an "ignitor", but it won't be affected by changes in resistance of spark plug leads.

.

 

[TxGSrider]

Nothing is going to mess with your CDI, mainly because you don't have one.

You DO have an electronic ignition module that Suzuki calls an "ignitor", but it won't be affected by changes in resistance of spark plug leads.

.

Ok, I was concerned electrical interference interfering with the electronics on the bike. I didn't want to trade one problem for another.

 

[Gorminrider]

It's more the coils themselves I'd worry about. When the secondary field collapses to create your" hotter" spark (if that's what you are after) it affects the primary as well...I don't know why people think they should redesign their ignition if it works properly as designed.

Fortunately, the cars beside you probably don't listen to am radio anymore and are protected by their metal shells too.

 

[TxGSrider]

It's more the coils themselves I'd worry about. When the secondary field collapses to create your" hotter" spark (if that's what you are after) it affects the primary as well...I don't know why people think they should redesign their ignition if it works properly as designed.

Fortunately, the cars beside you probably don't listen to am radio anymore and are protected by their metal shells too.

I'd think itd be harder on coils trying to discharge though a really high (bad) spark plug wire than one with little resistance? However, the real resistance Id have to guess comes from the gap at the spark plug. Theres allot of resistance to jump .025".

Oh, and I was reading my meter wrong... the 2 wires were reading between 10k and 12k ohms... not 10-12 ohms, and the other 2 were at 6.3k-9.1k. Seems like allot for a 6"-10" piece of wire.

 

[Gorminrider]

It's not really about how "hard" it is...when you start fiddling with what is essentially a step-up transformer, it gets complicated. You can tunnel into dwell and all that too....you pretty much end up in a night school course. Please do. We need an expert like that! but from my general opinions...

It's ok to put solid core wires on. In fact, I would. But I'd use caps with them, is all. But you have unstock coils with graphite+fibre wires and no resistor cap so I think you'll be choosing between about 5k and 10k caps. If you know what Accel had originally in the resistor-core wires, that's what I'd try at the caps on the high side maybe. or, if your Accel coils are really similar to the original suzuki ones, refer to that.

The thing unknown is whether you still have the original TCI box. It's less of a concern-I think they are tough, but if you recall the trouble with old-school points and capacitors, you really don't want excessive "backflash" in it either...who knows how the old resins and things are doing in there?

You can hunt the caps down at NGK . I can't remember which bike you have but off the top of my head. My 4 and twins all seem to be about 4.5 -5 k ohms through the cap....

 

[TxGSrider]

Just an update.

The new wires didn't solve the problem I having with my #3 cylinder fouling plugs after a few minutes... and #2 missing intermittently, so I decided to some testing.

Ive only got 9.35 volts to the coils (12.1-12.2 at the battery w/key turned on...slightly higher with key off).

I tested my "3 ohm" Accel coils and one was like 7.8 and the other like 8.1 ohms.

So I figured it was a good time to freshen up the ignition system.
I bought some new Dynatek 3 ohm coils.
I've got my new solid core wires with resistor caps.
Got new plugs.
And I'm going to do the "relay coil mod".

I dunno if it'll help the miss... but it will at least get my ignition system back into spec and one less thing I'll have to concern myself with for a few years.

 

[Gorminrider]

Ive only got 9.35 volts to the coils (12.1-12.2 at the battery w/key turned on...slightly higher with key off)

but the bike is not running at this point... If it's running (even badly) that voltage will go up when the charging system helps it..it's already enough to start the engine apparently.

I've got my new solid core wires with resistor caps.
Got new plugs

.that sounds good-might fix this:

and #2 missing intermittently

having my #3 cylinder fouling plugs after a few minutes

maybe, or might be something else -not ignition.

And I'm going to do the "relay coil mod".

yeah-well..FIRST I'd see if the problem is fixed without this ...an awful lot of motorcycles didn't come with this from the factory and seem to hum along fine without it. I know mine all do...It's just another thing to go wrong, imo...when the "Normally Open" relay's coil burns out from being closed all the time, your bike will STOP in a bad place. So at the least get a GOOD relay. I'd rather have a Normally Closed in every case anyways...and have it energized when I push the kill switch to OFF.

 

[Steve]

Just an update.
Ive only got 9.35 volts to the coils (12.1-12.2 at the battery w/key turned on...slightly higher with key off).

And I'm going to do the "relay coil mod".

BEFORE you cut any wires to install a coil relay, do yourself a favor and check voltages at the fuse box. :-k
Does not matter if the engine is running or not, but make these voltage checks as quickly as practical. Clip your meter black wire to a good ground, turn the ignition key ON, then check:
1. Battery +
2. "Live" side of MAIN fuse (is hot when the fuse is removed).
3. "Dead" side of MAIN fuse (not hot when fuse is removed).
4. "Live" side of IGNITION fuse.
5. "Dead" side of IGNITION fuse.
6. Orange/white wire at either coil.
7. Battery +. (Just to see how much it dropped during the tests.)
For bonus points, check the voltage at the other fuses, too, maybe even at a headlight or tail light terminal. Your whole bike might be suffering from low voltage, not just the coils.

One of the biggest culprits for low voltage is the ignition switch. It has to carry ALL the current that the bike uses, and is very susceptible to dirt and moisture, which will cause voltage drops. If you find that all the circuits are low, it would make more sense to install a "whole bike" relay mod.

... when the "Normally Open" relay's coil burns out from being closed all the time, your bike will STOP in a bad place. So at the least get a GOOD relay. I'd rather have a Normally Closed in every case anyways...and have it energized when I push the kill switch to OFF.

That will certainly stop power to the coils, but it won't do anything for ensuring proper voltage, which is what this thread is about.

.

 

[TxGSrider]

Thanks for the input guys.
Its got a new ignition switch, I had to buy one when I swapped the GSXR forks. I also cleaned all the connectors and fuses and dielectric greased everything, but I didn't check or clean the connectors coming from the fuse box. I'll try that this weekend.
Otherwise my new Dyna coils arrived last night and just for kicks I measured the ohms on them. They read 3.8 ohms... much better than the 7+ ohms on my ancient Accel coils.
Looks like I have my Saturday plan.

 

[Gorminrider]

That will certainly stop power to the coils, but it won't do anything for ensuring proper voltage, which is what this thread is about

Stop switch to run a relay is what I described... But it'd need some tinkering to make it work the way I describe. "proper voltage" is another thing altogether...getting exercised about the voltage drop on a non-running/not charging bike with an unknown battery condition etc... not to mention that motorcycle coils can make an awfully good zap at 8 volts too...

It can get rococco pretty quick...I have a bike here with a relay that runs the starter relay. It also has a relay on the headlight..but these both seem to be intended for the purpose of keeping the headlight off until the bike is started ... But it does not have a relay on the ignition.