Topic: 1972 CB500 *problems* -__-

[josherr]

What's up guys new member to the forum
New rider but basically new everything
after buying a cb 500 awhile back and now a week after getting this bike out of a shop that got it up and running for me or I noticed the last carb on left side would leak gas after the bike sat for a minute or so


I started doing dome research and found the floats usually get stuck and overfills the carb but then I noticed the first pipe of my exhaust wouldn't get as hot as the other pipes and didn't get discolored like the other ones


Any help at all at what might be the problem ?
Is this something that I can take care of myself ?keep in mind I've never owned a bike or really worked on bikes either but I can be pretty handy and learn fast
Thanks any help would be appreciated





Sent from my iPhone using Tapatalk

[onetruepunk87]

Usually if a float is stuck you can whack on the side of the carb and get it to unstick. Don't use anything too hard, piece of wood or handle of a hammer. Do you know if the shop you brought it to went through the carbs and cleaned everything? They can also leak if there's a crack in the float bowls tube or if the float height is wrong.

As for the exhaust pipe being cold have you checked to see if that cylinder is firing?

[josherr]

How would I check if the cylinder is firing ?


Sent from my iPhone using Tapatalk

[Stev-o]

How would I check if the cylinder is firing ?

Pull the spark plug, reconnect it to the wire, lay it on the head and crank the motor for 3 sec. You should see a nice blue spark

[Restoration Fan]

How would I check if the cylinder is firing ?


Sent from my iPhone using Tapatalk

Pull that spark plug wire.  Either remove that spark plug from its spot or use an extra spark plug (what I do) and put it in the wire.  Then, hold the spark plug somewhere against the engine (I usually do it around the fins) and crank the bike.  If it's firing, the spark will jump/arc to the fins on the case and you know that cylinder is getting spark.

[riverfever]

Great looking bike. Check that number 1 plug and see if you're getting spark. I have a 71 500 and also had never owned a bike before. It's not horrible and this has been an amazing community. Everyone is willing to help you. Ask questions.

[calj737]

Since #1 doesn't get "as hot", I believe you have spark, but no fuel going to that cylinder. The float is probably stuck, and the jets clogged preventing fuel from entering the combustion cycle. If you had no spark, your cylinder/pipe would be cold as ice.

Address the carb sticking float as suggested by rapping on the body of the carb with a rubber handle. If it does not stop leaking, shut off the petcock, and open the drain screw on the bottom of the carb bowl (large flat blade screw). Gas will run out of there, so have a small catch cup. Rap the carb body while its draining and examine the gas afterwards. Dirty, floating gunk in it? If so, clean the interior of your tank and rid it fully of rust. If you don't, you will have persistent problems with debris, stuck floats, and intermittent firing on the cylinders.

[josherr]

Thanks fellas will try everything you guys suggested
Thank god for this forum haha or else I would be even more lost



Sent from my iPhone using Tapatalk

[Tews19]

Cal hit it in the head. Curious as to what the shop did to your bike? Please do not say they cleaned the carbs??