Replace Spark Plug Cap???

NoVa Rider · 05-28-2017, 06:47 AM

Over on ADVriders there is a post recommending replacement of the stock spark plug cap with an NGK cap to improve connection with the spark plug. This is a cheap swap, and having replaced spark plug caps on other bikes, I went ahead and did it.

I now think this is not such a good idea.

The stock RX3 spark plug cap is crimped onto the spark plug wire. You cannot simply unscrew it and replace it with a generic NGK replacement. You need to cut the wire. (It appears on the CSC parts diagram that the cap and wire come as a single unit.) Also, the OEM cap uses a simple direct metal connector between the wire and the plug. Unlike NGK caps, it is not a resistor design. Finally, the wire itself is not a copper core wire. It is more difficult to set the screw in the NGK cap. So while the NGK cap may offer a better connection with the spark plug, I think you end up with a weaker connection between the cap and the wire, and more resistance in the circuit that the OEM design.

If you decide to go this replacement route, I found NGK VB05F (NGK stock number 8032) was a duplicate for the size and angle of the OEM cap.

But if I had it to do over again, I would not go this route. If I suspected the OEM cap was loosing contact with the plug, I'd consider getting a new OEM cap and wire.

05-28-2017, 06:47 AM	#1
NoVa Rider Join Date: Jan 2015 Location: Northern Virginia Posts: 144	Replace Spark Plug Cap??? Over on ADVriders there is a post recommending replacement of the stock spark plug cap with an NGK cap to improve connection with the spark plug. This is a cheap swap, and having replaced spark plug caps on other bikes, I went ahead and did it. I now think this is not such a good idea. The stock RX3 spark plug cap is crimped onto the spark plug wire. You cannot simply unscrew it and replace it with a generic NGK replacement. You need to cut the wire. (It appears on the CSC parts diagram that the cap and wire come as a single unit.) Also, the OEM cap uses a simple direct metal connector between the wire and the plug. Unlike NGK caps, it is not a resistor design. Finally, the wire itself is not a copper core wire. It is more difficult to set the screw in the NGK cap. So while the NGK cap may offer a better connection with the spark plug, I think you end up with a weaker connection between the cap and the wire, and more resistance in the circuit that the OEM design. If you decide to go this replacement route, I found NGK VB05F (NGK stock number 8032) was a duplicate for the size and angle of the OEM cap. But if I had it to do over again, I would not go this route. If I suspected the OEM cap was loosing contact with the plug, I'd consider getting a new OEM cap and wire. Last edited by NoVa Rider; 06-06-2017 at 05:15 PM.
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