One Cylinder not firing - Honda Rebel Forum
Thread Tools Display Modes
post #1 of 13 Old 11-23-2012, 06:36 AM Thread Starter
Join Date: Aug 2012
Location: UK
Posts: 18
One Cylinder not firing


I probably have a very simple problem. But I am unsure where to start.

I tried to start my bike up the day before yesterday, and only one cylinder seems to be firing. When I pulled out the spark plug boot on the left the engine kept running, and when I pulled out the one on the right, the engine stopped.

This just about concludes my technical knowledge of engines. lol

I am guessing that there is a very simple set of procedures or things to do or check.

And I know that as you are a set of all round good guys on here, you will help me!!

Is the 1st step to take out the spark plugs and look at the colour of them??

I am totally guessing here.

Kind regards,
thebigconsultant is offline  
Sponsored Links
post #2 of 13 Old 11-23-2012, 07:23 AM
wjmrty's Avatar
Join Date: Feb 2011
Location: Melbourne,Victoria. Australia
Posts: 7,771
I would check your spark plugs first ,if 1 plug is wet & or oily replace them first

2000 rebel 250 Aussie My Baby.
2012 honda PSX 150cc scooter [in Thailand]
1986 rebel Silver 450 Elvis

putting your bike info in your signature helps others help you !
wjmrty is offline  
post #3 of 13 Old 11-23-2012, 09:16 AM
gyrojunkie's Avatar
Join Date: Sep 2011
Location: Astoria, Oregon
Posts: 6,150
The next simple test you can do is switch the plug wires and see if the other side then fails.

If not then then check for spark. with the plug out and connected to the wire, ground the plug to the engine as you crank the engine over look for a blue spark in the plug gap.

1. if you have spark check for compression.
2. if no spark check coil and CDI.
gyrojunkie is offline  
post #4 of 13 Old 11-23-2012, 09:42 AM
Join Date: Aug 2008
Location: Monroe, Louisiana
Posts: 28,935
I had a similar problem on my 2001 Rebel - until I cleaned the carb.

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:
flitecontrol is online now  
post #5 of 13 Old 11-23-2012, 10:03 AM Thread Starter
Join Date: Aug 2012
Location: UK
Posts: 18
Hi, thanks comrades!

I have checked that it sparks, which it does, when held against engine.

There was some soot, so I wire brushed it and cleaned it anyway with carb cleaner.

In fact, the bike runs when the plug is out on one cylinder.

My mate said that sometimes the fuel line or carb gets blocked up, so spray some carb cleaner down the fuel line, after unattaching from the On/Off valve at the tank.

I am guessing it has compression as I could feel it on my hand. But I have no way to check if it is correct?
thebigconsultant is offline  
post #6 of 13 Old 11-23-2012, 10:24 AM
Join Date: Nov 2012
Location: Hayward, WI
Posts: 34
hook it all up and fire her up. turn the lights off and see if the bad side is grounding out some where near the plug with it installed.
cruiser150 is offline  
post #7 of 13 Old 11-23-2012, 08:16 PM
gyrojunkie's Avatar
Join Date: Sep 2011
Location: Astoria, Oregon
Posts: 6,150
Try testing the compression with your thumb. pull both spark plugs out and with the kill switch engaged try to hold your thumb in the spark plug hole while you crank. check both sides to see if compression feels the same.
gyrojunkie is offline  
post #8 of 13 Old 11-23-2012, 08:22 PM
Duckster's Avatar
Join Date: Apr 2012
Location: Fredericton,NB
Posts: 13,265
Assuming you have a single carb rebel, If it runs OK on one cylinder its not a carb issue since the carb is common to both cylinders.

2004 Rebel 250, 2003 BMW K1200GT (roadburner), 2004 BMW R1200GS(all purpose),
1973 Norton Interstate (in a box in the basement)
1968 Triumph Bonneville
Duckster is offline  
post #9 of 13 Old 11-26-2012, 01:30 AM
Rebelpastor's Avatar
Join Date: Oct 2012
Location: Maryland
Posts: 5
I think, if we are to be of more help to you, we should nail down what kind of bike we are talking about. Your profile says you have a 125cc Rebel. Educate me here; did they actually make a 125cc Rebel? I've never heard of one. Does your bike have one or two carbs?

2004 Honda Rebel CMX250C
Rebelpastor is offline  
post #10 of 13 Old 11-26-2012, 01:54 AM
Buickguy's Avatar
Join Date: Mar 2010
Location: Michigan, near Ann Arbor
Posts: 17,771
Honda offered the CA 125 Rebel in Europe and some Asian markets. I was never offered in the U.S. (Kind of a pity, I wouldn't mind having one)

From what I know of the CA 125, its is a single carburetor model. The carburetor is not the CV type we are accustomed to on our CMX 250 C U.S. Rebel.
Instead it uses a variable Venturi (throttle slide) type of carburetor.
Here's a simple diagram of a typical variable Venturi carburetor.

1987 CMX250C Rebel
2002 FSC600 SilverWing
1983 Yamaha Midnight Virago XV920MK
Put your bike's year and size in your signature.
It helps others help you.

Buickguy is offline  

Quick Reply

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


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

Email Address:


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