using a nc24 CDI on a nc21, help needed

Forum rules
Please can you post items for sale or wanted in the correct For Sale section. Items / bikes for sale here will be removed without warning. Reasons for this are in the FAQ. Thanks
Post Reply
bay031
One Hit Wonder
Reactions:
Posts: 1
Joined: Sat Sep 01, 2018 1:23 pm
using a nc24 CDI on a nc21, help needed

Post by bay031 » Sat Sep 01, 2018 1:36 pm

Good day all,

I am a new member and not sure if this question has been raised before,

i recently bought a Honda VFR NC21 which i got for a steal due to no spark, i suspect the CDI unit went bad.

Upon inspection i noticed there is currently a NC24 CDI unit in the bike.

Due to the rarity of NC21 units in South African and the NC24 units being common my question is can i use a NC24 unit on my NC21?

From what i have observed the major difference is the 2 pin cam sensor plug not being present on the NC24 CDI unit.

TIA

magg
Senior Member
Reactions:
Posts: 1910
Joined: Mon Sep 20, 2010 11:55 pm
Bike owned: VFR400
Location: Blue Mountain NSW Australia
Re: using a nc24 CDI on a nc21, help needed

Post by magg » Sun Sep 02, 2018 5:54 am

It has the NC24 unit plugged-in and there is no spark?

From the info I have the NC24 ignition unit may function with an NC21 by simply by ignoring the cam sensor, although wiring setup my need rearrangement.
The P/N for the crank trigger mechanical parts appear to be the same for NC21/24/30 models.

Or perhaps someone on this forum has an NC21 ignition unit for sale.

decngb
Settled in member
Reactions:
Posts: 47
Joined: Mon Oct 16, 2017 3:58 pm
Bike owned: NC21, NC24, NC30, VFR800, MC19
Location: Georgia, USA
Re: using a nc24 CDI on a nc21, help needed

Post by decngb » Sat Sep 29, 2018 2:22 pm

NC21 CDIs are available on eBay. Here's one in the UK for 25 British Pounds that looks like it will ship just about anywhere.

https://www.ebay.com/itm/HONDA-VFR400-V ... Swpblbr1~D

I would be worried that someone rearranged the wiring. I just compared the wiring diagrams for the two bikes and noticed that the wire colors are mostly different. That makes me wonder about pin position as well.

You may have already done it, but I would check all the easy things first - wiring to kill switch, neutral switch and clutch switch. On my NC21, the problem was a broken wire in the kill switch circuit. On the NC24, it looks like the problem was a loose electrical connector.


Post Reply