Just a question in regards to the tune up kit. I see it's the NGK SD05F 500 ohm caps, and 7mm Suppression core wire. I really wanted the aesthetic of braided cloth covered spark plug wire that Tons performance makes. Gives it a real retro vibe, but that's just standard copper core.
The kit sold here lists suppression core, but when I look that up it sounds like it's 500ohm wire. So the question, does the VT600 need 1,000 ohms, 500 at the cap, 500 in the wire? Or am I not understanding this properly?
@danandersen9924 copper core wires dont resist electrical noise, and you've got 4 wires. Each fire sends a high voltage pulse that is like a tiny radio transmitter. It creates electromagnetic interference that may mess with the ICM and other electrical equipment. Suppression core is a far superior alternative to copper core wire. These hondas arent old harleys running 2 plugs and no resistor caps. Any modern ignition system that uses a CDI requires suppression core wire. this is why i include it in the kits.
Copper core is only for points ignition or magneto systems with no electronics.
I'll try to break it down for you
the suppression core wire uses a spiral wound core to slow down and smooth out the current pulses. Its purpose is to reduce high frequency EMI (ElectroMagnetic Interference) noise along the whole wire.
The resistor caps have a built in resistor that dampens the initial voltage spike at the spark plug tip and reduces radio interference right where the spark is happening.
Modern ignition systems — especially CDI, EFI, and digital ignitions — are crazy sensitive to electrical noise.
That spark pulse creates a massive voltage spike (20–40kV), which can:
- Induce false signals in the ECU or ignition pickup
- Cause misfires or weak spark at high RPMs
- Create radio/Bluetooth interference
- Corrupt sensor signals
Using both a resistor cap and suppression wire creates a two-stage filter that prevents that noise from back-feeding through the harness or frying sensitive circuits.
If you dont use them and decide you try and run copper core, you are pretty much spitting in the face of reason and reality and asking for shit to go wrong on your bike.
If you have no resistor caps, youll get spark plug noise, no suppression wire, you will get EMI running up the wire, ignition interference, erratic timing and CDI failures. so the suppression core wire + resistor cap and DPR8EA9 spark plugs are a noise controlled chain to prevent damage to the capacitor discharge ignition or CDI. This keeps your timing rock steady and reliable.
If you want cloth covered wire - go get an old points ignition harley and knock yerself out LOL
@TJ 10 4 boss, really appreciate the depth. Multiple other forums have misleading information, essentially that the resistor cap is the importance. The bright side is they make wire covering that mimics the old style and can be used on any wire for my aesthetic purposes, but I do want proper functionality. Thank you so much!@TJ
