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Discussion Starter · #1 ·
So I'm new to bike machanics and I picked up a 1981 Gl500I silverwing. (2nd bike I've owned) I'm having some issues and I just created more and I'm lost.
Issue 1- the left cylinder is back firing and is a mix of cold and hot air. I suspected spark so I swapped the coils witch throws me to issue two.
Issue 2- After I swapped the coils I can turn the key on no issues crank the starter no issues but as soon as I put the kill switch to run all lights dim out for 3 seconds then blows the 30 amp fuse. I swapped the coils back and still dose this.
My brain is hurting from diagnosing and fixing this bike past 3 days till 2am any advice, info' or recommendations would be amazing.
 

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My first suggestion would be to download a copy of the factory service manual (FSM) for your bike from the wiki (see link in my signature)..
Is the fuse blowing happening while using the start button, or as soon as you turn the kill switch to on, before engaging the starter?
For the fuse to blow you have a short circuit somewhere, created during the coil swapping operation. Replace the fuse with a 12 volt test light. That will light if there is a short. Examine what you did when you switched coils, which wires were disconnected and where they were reconnected.
 

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Discussion Starter · #3 ·
My first suggestion would be to download a copy of the factory service manual (FSM) for your bike from the wiki (see link in my signature)..
Is the fuse blowing happening while using the start button, or as soon as you turn the kill switch to on, before engaging the starter?
For the fuse to blow you have a short circuit somewhere, created during the coil swapping operation. Replace the fuse with a 12 volt test light. That will light if there is a short. Examine what you did when you switched coils, which wires were disconnected and where they were reconnected.
I've redone and found the short about 10 min ago and was able to get it to stop but I was blowing with in 3 seconds of switching it to on.
Now tho my left cilinder is still miss firing and blowing cold air out of the exhaust and now I can rule out coils. Timing is correct. Stator test came back fine. Carbs were redone and set to spec. So I'm at a loss
 

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81 Gl500i 83 CX650E
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Switch sparkplugs side to side.
 

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These ignition systems are quite robust. The most likely source of an ignition problem is the plug wires and caps. The spark plug cap contains a resistor. They are prone to corrosion.
This is a good article to review. Ignition Problems

To rule out a carb issue you might try injecting some fuel into the balance port on the intake. If the cylinder then fires suspect a carb problem. For some information on cleaning the carbs see Carb Cleaning by Larry - Honda CX and GL Wiki
 

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'84 CX650E that is evolving into a GL500
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What they said ^^^ The first thing to do is figure out whether the problem is fuel or spark.

BTW: Welcome to the forum. Please add your location and your bike's model and model year to your profile so that you don't have to remember to tell us every time and we don't have to keep asking when you forget (see Forum Settings link in my signature).

And welcome to the world of antique vehicle ownership (they own us, not the other way around). Your bike is about 4 decades old and the Previous Owners may or may not have done the maintenance necessary to keep it safe & reliable so download the Factory Shop Manual for your model like Mike mentioned (there's a link to the CX Wiki in my signature too) and once you get this issue figured out go through all of the service procedures, regardless of whether your bike has reached the specified mileage.
I also recommend looking on all rubber parts with suspicion because rubber does not age gracefully. Check the date codes on your tires and replace them if they are over 5 years old no matter how good they look & feel (old rubber simply cannot flow around the irregularities in the asphalt well enough to grip, especially if it is cool or wet). If your bike still has the original rubber brake line(s) (should be replaced every 2 or 3 fluid changes = 5 or 6 years) I recommend shopping for modern stainless braided ones (they last practically forever and double the life of the fluid). And don't forget things like the rad hoses and the boot between the engine and swingarm (they can crack on the bottom where you don't see it).
 

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Given that these are 12 volt coils what would be the effect of wiring them in with the wrong polarity?

Would powering the trigger side rather than the power side blow fuses?

I don't know, I work with CDI so just guessing here...
 

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Discussion Starter · #8 ·
Given that these are 12 volt coils what would be the effect of wiring them in with the wrong polarity?

Would powering the trigger side rather than the power side blow fuses?

I don't know, I work with CDI so just guessing here...
I Figured it out I pulled the head and the last owner that tore the engine down didn't put the exhaust valve pushrod back in. So after reinstalling it putting a little starting fluid to make the carbs suck up gas boom starts up with one fast hut if the start button and sounds amazing.
 
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