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Discussion Starter · #1 ·
Hello I recently bought a 1980 honda cx500c. .. i got it from a friend at work and he had the carbs off of it as far as I know the bike was last registered back in 94 and could of just sat since then. The kids dad thought he was gonna have it for a bit and bought a jet kit for it before I got it. I've had it running for about a month since putting that jet kit in his dad got... now this last couple days I was just letting it run for fun in the garage, im looking to put "pods" on eventually and was looking at the intakes with it running..I just put a water pump cover gasket on for a coolant leak and when looking to check for leak again I noticed that the left cylinder doesn't seem to be firing. At that time I had my hand on cylinder head walked around to the right side n burnt my hand on the right cylinder head lol...i have the boots off to the air box and put my hand by the right intake and can feel the airflow but on the left theres nothing. ...swapped coils with plug wires side to side to test if it was a coil and there was no change...so thinking that. The coils are ok I swapped them back to the original side...so without having a multimeter I checked and I do have spark so I sprayed starting fluid in left side only and even that didnt get to fire....so I took carbs out and played with them thinking fuel wasnt getting to the left and now I have this other problem where gas will pour from bowl drains first the right side did it and then only the left side...

So basically left cylinder wont fire even after swapping coils with plug wires still attached and starting fluid and gas will pour out the bowl drains... thanks in advance.
 

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sounds like the carbs need help but check the left cylinder to see if it's firing the plug.... just put the plug on the head & crank it. it's possible the coil isn't getting a pulse from the ignitor
 

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Discussion Starter · #3 ·
Yeah I checked that before...it has spark but could be weak thst made me think it wasnt getting fuel so I just shot some starting fluid in the left side for the heck of it and it still wouldn't fire...

So it has spark but wont even fire with starting fluid?
 

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Discussion Starter · #4 ·
Im leaning towards that little black box idk what to call it but the wires from it go to the coils
 

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That's the CDI box and is one possible source of your problem.

Get a multimeter and run through this. The CDI box can't output quality power without quality power going in.

 

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Since you can't feel the airflow on that side there's no compression. Adjust your valves and cam tensioner before messing with electrics. Once adjusted try again, if no go, check compression.

On a bike that sat that long, there's a good chance moisture got into the cylinder and messed it up. If compression is way low, inspect the cylinder for rust damage. May need a re-hone and rings.
 

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Discussion Starter · #7 ·
Hey guys thanks for the inputs...the left cylinder seems to have compression..I took the plug out and put my hand over the hole and it'll push air out with my hand over the hole...I tried a compression gauge but it wasn't long enough to work... i sprayed starting fluid in n left plug out n hit the starter n I shot out a good puff. Im going to have to find my multimeter and run that test i'll post my findings when I do.. i had the right plug unplugged n put starting fluid in the left and got a couple little "thump" sounds but that was all.but in the meantime of looking for my meter im going to get a can of carb cleaner and spray the heck out of carbs n clean them some more.
thanks again
 

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Carb cleaner will destroy the rubber parts in the carb... One must completely disassemble the carbs if you intend to use carb cleaner on em...
 

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I find aerosol carb cleaner too volatile to adequately do the job. It's best for checking that passages are clear.

It's better to remove the rubber and plastic parts and dump the whole thing in a 50/50 mix of acetone and acrylic thinners for a day or two. This loosens upall gums and varnishes.

Ultrasonicing after is good if you have the equipment but the dip will clean things pretty well.
 

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Discussion Starter · #10 ·
The left side fires now...I cleaned the carbs out again, wont surprise me if i'll need to do it again. Any ideas on how to jet the floats to not stick cuz gas will just piss out the bowls and i've tried to clean it up already?....
 

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Discussion Starter · #11 ·
Get not jet lol...still havent tested the stator n stuff all out but the bike runs at 13 n change volts running but wont get up of 5k rpm so sounds like the high end of stator is out.
 
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