[Captainkirk1234]

Background:

First of all, I'm a rookie at this so go easy on your reply so I can keep up. I got my dad's old 1972 CL350 that has been sitting in a Quonset Hut for 35 years - dry environment but fair share of mud daubers and spiders made a nice home over time. I cleaned tank/fuel system & carbs (among other things). I got it running but here is what I'm experiencing:

1) The output exhaust from one of the cylinders has good pressure and it feels warm when I put my hand close to the tailpipe. The other tailpipe is not putting out nearly as much "pressure"; and the air is cold.
2) I followed the "warm" tailpipe exhaust and disconnected the spark plug wire from that cylinder - the bike died.
3) I put the spark plug wire back on and restarted; disconnected the "cold" spark plug wire from the cylinder and the bike kept running.
4) I removed the spark plug from the cold cylinder and confirmed I had spark (as the bike was running).
5) I'm thinking something with the carb is not passing fuel into the cylinder...or maybe the intake valve is stuck...or something??

Any advise will be helpful. I'm sure once I get over this hurdle I'll have more questions. Thanks.

Kirk

 

[ancientdad]

Since the bike sat so long and the carbs obviously needed to be cleaned, it's a good guess the carb on that side isn't yet clean. Does that cylinder run once you raise the revs a bit?

Also, now that you're here, you should have a look at this

https://www.hondatwins.net/forums/23-member-introductions/121120-critical-read-before-posting.html

 

[Captainkirk1234]

Hey, thanks for the quick reply. Yes, I pulled both carbs off; broke them down and gave them an ultrasound bath - put new components back in from Common Motor. The float on one of the carbs was questionable (pin was a bit rough and the float was stuck once in a while; I've since ordered new floats and pins from CM - waiting on them so I can install next weekend). I can rev the bike but I don't hear any difference out of that cylinder. I'll check out the link you suggested.

 

[TOOLS1]

This is very common on these bikes. First, put the original Honda brass parts back into the carbs. Then go to your local Honda dealer and get new O-ring packing kits for them, they are still available. After doing this check for vacuum leaks. I use starting fluid for this. Be sure to check the throttle shaft seals. For some reason the inside seal on the left carb always wants to leak. I repair them by replacing the felt seal with an O-ring.
TOOLS