Need Help Troubleshooting a CBX Problem

[Tom Neimeyer]

I've been working on a '79 CBX that has been sitting up for a while. I tilted the motor and cleaned the carbs. Nothing unusual, just blew through all the passages and put them back together. Put them back on and started the buke. It doesn't seem to be running on all six cylinders. In fact, it only seems to be running on 4, 5, 6. When I use a infared pyrometer, the exhaust on 1, 2, 3 run about 160 degrees. Cylinders 4, 5, 6 run 430-460.



I have checked the choke blades and they are open on all 6 carbs.



I can see the throttle shaft move.



I have spark at all cylinders.



It has fuel in all the bowls



I can not find any leaks on the carb boots.



All idle screws are set at 2 turns out.



This is very odd, most things that affect a CBX are in pairs, a coil affects 2 cylinders, a pickup effects 2 cylinders a spark unit effects 2 cylinders. I can't think of much that effects 3 cylinders.



I do not know how the bike ran before it sat and the carbs got gooped up.



I will try a compression test or a leakdown test sometime in the next few days.



What am I missing?



Any ideas would be appreciated.



Thanks, Tom

[broook]

Foolish suggestion # 365. Could one of the mufflers be slightly plugged up. Also the fuel line to #123 carbs could be sucking together.

[Tom Neimeyer]

Bob,

Thanks for the suggestions. The I'm pretty sure 1, 2, 3 are getting fuel and it has to get past 2 & 3 to get to 4, 5, 6. The exhaust is a Max X a 6:1:2.



I am thinking the cams might be in 180 degrees off. I do not know who assembled the motor but I am going to open it up Tuesday.



Thanks again, Tom

[Jim-Jim]

Tom,

Really interesting problem; let us know how it turns out. I like to file these things away for future reference in my 'encyclopedia' that I'm building up. Never know when it can pay off in the future. Thanks.

And good hunting!!