1993 Nighthawk 250 has no spark - Honda Rebel Forum
Reply
 
Thread Tools Display Modes
post #1 of 55 Old 04-21-2011, 05:28 PM Thread Starter
 
Join Date: Apr 2011
Location: Cedar Park, Texas
Posts: 31
1993 Nighthawk 250 has no spark

It is my understanding that the Nighthawk and Rebel 250 are very similar, so I hope no one minds me posting a Nighthawk problem here. I have a 1993 CB250 Nighthawk that does not have any spark at the plugs (installed new plugs). The engine turns over great and all of the lights work. I have performed the following tests using my factory Service Manual for procedures and specifications. The only thing I saw that was a bit off from the Service Maual specifications was the Primary Ignition Coil reading at the CDI connector. My Ohm reading was 3 as opposed to the 8 - 15 as referenced by the Service Manual. Any ideas would be greatly appreciated.

CDI Module: Is there a way to test the module? I did not see anything in the Service Manual.

Coil 1:
3.08 ohms with digital meter on 20k setting and cap disconnected (one lead on terminal and one at end of wire)
7.45 ohms with digital meter on 20k setting and cap connected (one lead on terminal and one at end of cap)
0.2 ohms with analog meter on RX1 setting (One lead on each terminal)

Coil 2:
3.09 ohms with digital meter on 20k setting and cap disconnected (one lead on terminal and one at end of wire)
8.15 ohms with digital meter on 20k setting and cap connected (one lead on terminal and one at end of cap)
0.2 ohms with analog meter on RX1 setting (One lead on each terminal)

Excitor Coil: 132 ohms with digital meter on 2000 setting (taken from primary connector as per Service Manual)

Pulse Generator: 121 ohms with digital meter on 2000 setting (taken from primary connector as per Service Manual)

CDI Connectors (Readings taken from the two connectors that plug into the CDI Module)

Ignition Primary Coil: Black/Yellow to body ground registered 3 ohms with digital meter on 2000 setting (According to the Service Manual this reading should be bewteen 8 - 15 Ohms)

Pulse Generator Coil: Blue/Yellow to body ground registered 128 ohms with digital meter on 2000 setting

Excitor Coil: Black/Red to body ground registered 132 ohms with digital meter on 2000 setting

Neutral Switch Line: Green/White to body ground registered continuity when in neutral

Side Stand Switch Line: Green/White to body ground registered continuity with stand up

NOTE FOR NEUTRAL AND STAND LINES: Transmission had to be in neutral AND stand had to be up for continuity. If the stand was down and transmission was in neutral then there was no continuity. Same thing if the transmission was in first gear and stand was up.

Ground Wire: Green to body ground registered continuity

Ignition Switch: Headlight, Tail Light, Instrument Lights and Turn Signals work. Engine turns over great when ignition is on and starter button is depressed.

Off/Run Switch: Black/White to body ground with Ignition Switch on and Off/Run switch in Run position did NOT register continuity. The switch is suspect. If I understand how the switch works then the ground circuit is completed when the switch is in the Run position. What I did was bypass the switch by disconnecting it behind the headlight and ran a wire directly from the wire to ground. I then had continuity, but still no spark at the plugs.
Caracal is offline  
Sponsored Links
Advertisement
 
post #2 of 55 Old 04-21-2011, 05:42 PM
Moderator
 
Join Date: Aug 2008
Location: Monroe, Louisiana
Posts: 28,295
I suck at electronics. Is this any help?: http://www.electrosport.com/technica...ng-diagram.pdf

Keepin' all the left over parts. Gonna use 'em to build another bike!

'01 & '09 Rebel 250, '06 Ninja 250, '89 VN 750
Putting your bike year and model in your signature helps others help you!
Here's how: https://www.hondarebelforum.com/f19/...re-121087.html
flitecontrol is offline  
post #3 of 55 Old 04-21-2011, 08:04 PM Thread Starter
 
Join Date: Apr 2011
Location: Cedar Park, Texas
Posts: 31
Thanks for the flow chart. I have seen it, but it seems to me that this is more of an ignition rather than a charging problem. The bike turns over, but there is no spark.
Caracal is offline  
 
post #4 of 55 Old 04-21-2011, 08:16 PM
Moderator
 
Join Date: Aug 2008
Location: Monroe, Louisiana
Posts: 28,295
Our electrical guru's will be logging on soon.

Keepin' all the left over parts. Gonna use 'em to build another bike!

'01 & '09 Rebel 250, '06 Ninja 250, '89 VN 750
Putting your bike year and model in your signature helps others help you!
Here's how: https://www.hondarebelforum.com/f19/...re-121087.html
flitecontrol is offline  
post #5 of 55 Old 04-21-2011, 08:16 PM
jax
 
jax's Avatar
 
Join Date: Nov 2009
Location: Atascadero Ca. 93422
Posts: 1,700
Garage
Good luck with the electrical problem. I have trouble with trying to figure out electrical problems.
My approach would be to check the kill switch first. Make sure the power is going in and out on the wires.
I don't know if the nighthawk has a kill switch.
Good luck

Ride Safe
Keep the rubber side down and the shiny side up
1986 450 Rebel
jax is offline  
post #6 of 55 Old 04-21-2011, 08:38 PM Thread Starter
 
Join Date: Apr 2011
Location: Cedar Park, Texas
Posts: 31
If I understand the switch correctly, turning the switch to "run" completes the ground circuit. I wasn't getting continuity when I checked the kill switch from the CDI connector as per the factory Service Manual, so I suspected the switch. I bypassed the kill switch by disconnecting the switch's connector behind the headlight and grounding it. I then had continuity. Still no spark at the plugs.
Caracal is offline  
post #7 of 55 Old 04-21-2011, 08:53 PM
 
Join Date: Jan 2010
Location: Summerfield,FL
Posts: 662
Greetings Caracal,

The run/kill switch operates like this. Run = switch open (no connection), kill = switch closed (grounded).
Soul Searcher is offline  
post #8 of 55 Old 04-21-2011, 09:04 PM Thread Starter
 
Join Date: Apr 2011
Location: Cedar Park, Texas
Posts: 31
Thanks, Soul Searcher! That makes sense.
Caracal is offline  
post #9 of 55 Old 04-21-2011, 09:11 PM
 
Join Date: Jan 2010
Location: Summerfield,FL
Posts: 662
You're welcome. What Brand and model is your digital volt meter?
Soul Searcher is offline  
post #10 of 55 Old 04-21-2011, 09:37 PM Thread Starter
 
Join Date: Apr 2011
Location: Cedar Park, Texas
Posts: 31
The multimeter is a Cen-Tech model 90899.
Caracal is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Honda Rebel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome