Firing on one cylinder any help fellas?

[airtrafficguy]

My dad has a 87 450 rebel like mine that is only firing on one cylinder. We had the carbs checked and they are fine. We took the coil off mine and put it on his... Still one one cylinder. Of course we tried new plugs, new wires, and wire ends. The only thing I guess is the stator or the CDI. If the CDI is bad will that cause it to fire on one cylinder or what? Any help would be greatly appreciated. Thanks

Corey

[Snorebaby]

Yes I would check the CDI for proper voltage/resistance. I am at work right now but I can look in my service manual and post the values and steps taken to troubleshoot later tonight. There is a post of the values for the coil/wires if you want to double check the resistance of them. Think it is under the header of Clymer Errors or somthing like that.

I had the same problem and it turned out to be the carb was flooding the cylinder. Put on a known good carb and it fired right up, both cylinders. My carb had been sitting for a while and cleaned it and it was out of adjustment. Check your vacuum hoses also coming from the cylinder to the carb & petcock. What does the spark plug look like when you pulled it -- Dry or Wet? Dry=no gas.

EDIT: Here is the link to the post mentioned above.....go with the values from the Honda Service Manual
http://www.hondarebelforum.com/phpBB2/viewtopic.php?t=273

[airtrafficguy]

when he bought the bike the guy had already put spark plugs in it but I know that it is not fouling so I'm thinking that the plug is not getting gas. Thats what led us to believe that the carbs were malfuntioning. We had them gone over by a very good mechanic who said they were fine. You are probably right though cause i'm thinking its the carb. The only reason we ruled that out was that we switched the plug wires around and it backfired out of the other pipe. Am I having a brain fart here. LOL I mean its like when you get it to a high RPM you can hear it trying to kick in but it never does. I'm with you man I think its the carbs but I will give the resistance figures to my mechanic and maybe he can shed some light on this. Thanks a lot for your help man!!!

[GearJammer]

Another thing you can do is compare the compression of both cylinders. Bad rings, valves out of adjustment, or stuck valves can prevent the compression needed for combustion.