black smoke out of exhaust?

Question

i have 76 honda CJ360
i had it for a month and it was running good and everything
i am not sure if it is relevent or not but it's got some rain yesterday but it was not first time it got rained over.
I started today and there was black powderly smoke out of exaust
everytime i rev it up
it then started to kinda like back fire every 5sec or so.. but it sounded like puffy sound not loud back fire sound....
it also had a leak where tip and the pipe meets, but i am not sure if it was there before or i just found out because it was black smoke, so that i could see it well.
WHAT DO I DO?
is it bad??

thank you.,

jun

Answer 1

Yeah, you definitely have some carbon build up. I highly doubt the rain had anything to do with it. You definitely need a tune up, probably spark plugs replaced, fuel injection cleaning, and they need to make sure you aren't burning any oil or fuel. Have them check for leaks while they're there, which they should do anyway. Good luck, and I hope it isn't a very costly repair for you. As long as it's just carbon, you'll be fine. Hope there's no leaks though!

Answer 2

hey jun,the black smoke coming from your pipes,and the funny sound means that your engine is getting too much fuel and not enough air.there is probably some trash in your carburetor.there is a small screen in a bowl under your fuel shutoff valve.it should be removed and cleaned out,as well as the bowl on the bottom of the carb.the trash in the carb is getting in the needle valve(also in the carb)and blocking it from shutting off the fuel.it is by no means a serious problem,but it will only get worse until you clean your tank and carb.if you have any more questions about it,feel free to contact [e-mail]

Answer 3

From my experience with carbs I suspect you either have dirt in the jet or your float is stuck.If you suspect dirty gas or old gas take the tank of and dump the fuel,put new fuel in the tank and while the tank is off you should be able to get at the carbs.Take off the bottom covers and clean out the float area.Make sure you don't make any sparks or smoke around the gas.Good luck,hopefully you can figure it out.Also if you don't have one install a filter in the fuel line going to the carbs at this time.

Answer 4

black smoke is gas. the moisture at the exhaust is either water blown in or un burned gas. your carbs may be leaking gas into the engine. Always turn the gas off, and if its gonna set for a while turn it off and run it out of gas. Check to see if the oil is overfull from gas, and change it if it is. then take it out and run it hard for a while, see if it cleans up.
you can duplicate this by turning the choke partially on while revving it. Blue stinky smoke is whats bad. the worst issue on the Cb360 honda series is cam recsssion caused by not changing the oil. take the points cover off, you will see the end of the cam. if you can lift it up and down, its getting worn.

Answer 5

alot of carbon buildup in the pipes. ur mixture might be a touch too rich. if the plugs are a golden brown, the mix is ok. u might have an exhaust manifold leak also. if so, u could actually be running too lean because with that leak, in a sense, ur pipes are now free-er flowing with lack of backpresssure. that might need just a retighten of the pipes at the manifold, or u might need to replace the gasket, then re-torque to specs. btw, runnin with the choke too long will cause an extra-rich condition that will foul plugs.

Answer 6

Lenoire...omg "make sure it's not burning oil or fuel"...last I knew a combustion engine burns fuel. Oh and as for fuel injection, it's a tad too old a bike for that. Jeesh! Rich fuel to air mixture (too much gas-faulty carb), bad compression (piston rings worn), valve seats (blow by), among others. Here are a few sites. My experience is from restoration of two bikes in previous two winters. There is nothing that you can not find on web! I repaired my freezer recently with no previous knowledge. "Troubleshooting" is a key search term to use. Good luck.

Answer 7

Black smoke is usually sign of too much gas going in and not being able to be burned, check to make sure the choke is completely off, then its time to ensure the floats in the carb is not jammed down, so remove and dissemble the carb and clean out all passages with carb cleaner, also check the plug is gaped to proper size.
If you were burning oil, it would be blue smoke.

Answer 8

You could still be running rich for some reason, or burning oil. I know a burnt exhaust valve will cause the same symptoms.


Is this the same problem as before, coming back?
I never found out how you got it running.

Answer 9

you are running rich your needles may not be able to seat if there is varnish in the carbs. Try a full tune up freash fuel,plugs,air filter,flush the carbs drain the bowls etc.

Answer 10

its an old motorcycle, so it may be alot of carbon built up in the engine, black smoke usually means too much fuel. id say just give it a tune up,