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Discussion Starter #1
Hey all, this is my first post but I just ran into a serious problem with my cx500c. First off let me say it is a 1982 Honda cx500c with about 15,000 miles on it. (or so it says). on one side of the engine block it has silicone running down the side. i'm sure someone before me has gotten into the engine. Okay so, my bike has been running great as of late. No problems all was smooth. We took off the seat and the tank and i were checking it over one day, we also changed the antifreeze. Anyways the next day my engine started leaking antifreeze, we replaced the o ring on the metal arm leading to the engine. (sorry guys i know zero technical terms). that seamed to fix the problem, now today I took it out to go to work and it started backfiring. at first it wasn't horrible and i figured it was running rich or i needed to clean the carbs. but but as i kept going the idle speed went lower and lower. eventually i had to keep the throttle open just to keep it going. when i was almost to work it started smoking massive backfires and eventually it died. i just was able to coast it into my work. Please Please Please help me!!!!!!!!!!! this is way over my head. I don't have a ton of skills and this is my first bike. I will say i'll do anything to get this up and running again.
 

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What colour was the smoke?

Check the oil. What do you see?

Check the coolant in the radiator under the fuel tank (not in the container behind the engine). What do you see?

What were the temp gauge and oil light showing while all this was happening?

Got a photo of this silicone? Is it at the back of the engine behind the metal pipe and down the left side, or somewhere else?
 

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Strange. There was no problem whatsoever (right?), then you decided to change the coolant (why?), and from then on it leaks coolant and you have serious engine problems.
 

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Check if it's not leaking coolant from the weep hole. It's in the back of the motor where you changed the O ring of the chrome arm going into the engine. It could be the O ring, but it could also be coming from the weep hole just next to it. Research weep hole, or waterpump.

I'm guessing the backfiring is just that it needs a very good carburetor cleaning.

And check JC's checklist :)
 

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Does the 82 CX have a vacuum line running off the fuel petcock? If so, it's critical that you attatch that line to the correct fitting. I believe it's the one closest to the front of the bike. Good luck
 

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Hi kskinny, sorry to hear of your problem! Let us know the info the guys are asking about in the questions above, no better help and knowledge than this forum for the CX.

Rambler is correct. The '82 has a vacuum petcock. The front most fitting on the vacuum side of the petcock needs to run down to the carb for vacuum.
 

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Discussion Starter #9
Thank you all so much for the response. I was going to start with a good carb cleaning. I figured that might be the most major problem. I'll post a picture of the silicone today so you guys can tell me if this is a huge problem or not. I'll check the oil and the coolant as well. i believe the vacuum hose is fine, well at-least it didn't look bad.
 

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Discussion Starter #11
white smoke, but it smelled like gas. It wasn't real bad white smoke but it was coming out my right exhaust. the oil also looked fine, i didn't see any antifreeze in the oil either. we took apart the cabs and the jet on the right side was plugged. only a very small hole could be seen. I cleaned the jets and am about to install the carb back on the bike.
 

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Wait............

You have only rinsed one jet. These carbs are finicky with proper cleaning. I'd suggest you get a copy of Larry's Carb book, then follow it to the letter. While you are waiting on the book and doing a proper cleaning, it would be a good time to begin checking the resistances of the ignition system; stator, coils, plug boots......etc. Maybe make a couple of minor upgrades like replacing the main fuse, replacing the resistor in the plug boots, replace the plugs with resistor types......many small but important mods can be done to improve the bike without a big spend.
 

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Discussion Starter #13
Wait............

You have only rinsed one jet. These carbs are finicky with proper cleaning. I'd suggest you get a copy of Larry's Carb book, then follow it to the letter. While you are waiting on the book and doing a proper cleaning, it would be a good time to begin checking the resistances of the ignition system; stator, coils, plug boots......etc. Maybe make a couple of minor upgrades like replacing the main fuse, replacing the resistor in the plug boots, replace the plugs with resistor types......many small but important mods can be done to improve the bike without a big spend.
That sounds like a good idea, i'm sure they all might need replaced anyways. when i took the carbs out we cleaned both sides and that seemed to solve the problem. the bike takes off and run fantastically. it is also idling properly one set of jets were clogged. I am still getting smoke out of the exhaust though. i also ran some sea-foam in the engine to help clean any carbon build up. I also know that makes it smoke up a little. the smoke has a straight exhaust smell though no gas or oil or antifreeze in it.

also i'm experiencing gas coming from the petcock through the breather hose. Is this a problem?
 

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Discussion Starter #15
Means that your float is sticking or out of adjustment allowing the bowl to overfill.
Are you saying the Float in the petcock or the float in the carbs. i have also heard that people say you can just clamp off the breather tube to the petcock since some don't even have any. Is this true.
 

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Float in the carb bowl.
Pinching off the tube is a bad idea. It's there to warn you about a problem, pinching it off will send raw fuel into the various internal circuits of the carb where it's not supposed to be.
 

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Oh, wait, you meant the petcock tube.
Again, bad idea for a different reason.
The vent tube is there so that the diaphragm can flex when vacuum is applied.
 

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Discussion Starter #18
What colour was the smoke?

Check the oil. What do you see?

Check the coolant in the radiator under the fuel tank (not in the container behind the engine). What do you see?

What were the temp gauge and oil light showing while all this was happening?

Got a photo of this silicone? Is it at the back of the engine behind the metal pipe and down the left side, or somewhere else?
cx500 silicone.jpg

here is a picture of my silicone. What do you think JC. does it pose a problem or did the person who had this before me not fine a gasket kit.
 

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Rear case was assembled with too much silicon. There may be a gasket under there or the water pump impeller would rub.
 
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