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1981 CX500C US Model - Caf茅 Racer
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Discussion Starter · #1 ·
Hi,

This is my first post but I've been using the forum for a few weeks now and have found it a fantastic source of information while fixing up my new toy, so thanks to you all for sharing your vast knowledge.

I've read a lot on here about GY6 modules and where to buy them, I know that Murray has them listed at a very reasonable cost. However; I'm in the UK and the shipping costs are higher than the parts.

Would anyone have any ideas of where else I could source the correct modules from closer to home?
Or what the difference is between the different models? They all appear to have the same part number!
I made the mistake of buying the ones being sold on Amazon, they have the same connectors but are physically smaller, they also make a nice popping sound the first time you switch on the ignition.

Thanks in advance 馃憤
 

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Have you installed a Rae-San ignition on your bike?
 

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'84 CX650E that is evolving into a GL500
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I can't answer your question but welcome to the forum 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 it is highly recommended to download the Factory Shop Manual for your model (available through the CX Wiki - link in my signature) and 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).

The best advice anyone can give you about customizing any vehicle is to get it safe & reliable in more or less original condition and use it for a while before you start making any changes so it can tell you what changes it needs to make it do what you want/need better. That approach almost always results in something you actually want to keep and use but making changes based on style or on what someone else (who may or may not really understand how the changes affect the way it works) has done often results in a piece of expensive yard art that you can't stand sitting on for more than a few minutes and might even be dangerous.
 

Registered
1981 CX500C US Model - Caf茅 Racer
Joined
9 Posts
Discussion Starter · #5 ·
Have you installed a Rae-San ignition on your bike?
Yes, it has the Rae-San kit with stock CDI which was already installed when I bought it.
The bike runs well occasionally but mostly 1 of the cylinders drops in and out, I swapped the GY modules over and the problem was transferred so I'm planning on replacing them both. 1 of the modules is also emitting a high-pitched squeal.
 

Registered
1981 CX500C US Model - Caf茅 Racer
Joined
9 Posts
Discussion Starter · #6 ·
you can try here
dc-cdi gy6

Rayman
Thanks Ray I'll give them a try.

When I was doing a bit of research last night I came across this wiring schematic which might explain why the Amazon modules didn't work, I guess they might have been the AC type?
208277
 

Registered
1981 CX500C US Model - Caf茅 Racer
Joined
9 Posts
Discussion Starter · #7 ·
I can't answer your question but welcome to the forum 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 it is highly recommended to download the Factory Shop Manual for your model (available through the CX Wiki - link in my signature) and 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).

The best advice anyone can give you about customizing any vehicle is to get it safe & reliable in more or less original condition and use it for a while before you start making any changes so it can tell you what changes it needs to make it do what you want/need better. That approach almost always results in something you actually want to keep and use but making changes based on style or on what someone else (who may or may not really understand how the changes affect the way it works) has done often results in a piece of expensive yard art that you can't stand sitting on for more than a few minutes and might even be dangerous.
Great advice, thanks Bob.

1st job was to get her through an MOT which meant new front disks & pads + servicing the calipers along with new brake fluid, now all done and road legal. Next job is a service and to sort out the electrics to get the engine running right so I can enjoy the summer with a reliable bike. Then maybe over the winter, we might get a new paint job 馃榿
 

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there are AC and DCI cdi modules as your research has indicated -
there are also several types of DC_CDI - the ones for chinese engines ( eg gy6) and the ones for Japanese engines - different trigger behaviours and polarities.

I use the GY6 DC-CDI in the large case from Wingsmoto.

Rayman
 
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1981 CX500C US Model - Caf茅 Racer
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Discussion Starter · #9 ·
there are AC and DCI cdi modules as your research has indicated -
there are also several types of DC_CDI - the ones for chinese engines ( eg gy6) and the ones for Japanese engines - different trigger behaviours and polarities.

I use the GY6 DC-CDI in the large case from Wingsmoto.

Rayman
Hi Ray,

I bought a couple of those CDI modules from eBay but when they arrived I noticed that they were the smaller type, although the box stated they were DC so I gave them a try and they worked, or at least I think they did!

The bike starts every time and idles perfectly now but doesn't feel as responsive, when I took it out for a ride I found that the engine only revs to about 4000rpm and then pretty much stops pulling. I tried pulling the choke out but that causes the revs to drop off and the engine to lose power.

I've had the carbs on the bench a couple of times over the past few months and carried out basic cleaning but they were spotless, and I'm sure Ianjenn overhauled them when he built the bike. I know fuel delivery to the carbs is good as I've tested the flow, I also have an in-line fuel filter fitted.

So I'm wondering if these CDI modules could cause this if they're not quite right for my bike? Do you know if that's possible or am I barking up the wrong tree?

TIA
 

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I use the DC-CDI that I use in a "special way" . I trigger them so that they fire immediately - defeating their internal advance calculation so that I can perform the advance in my controller.
Other CDIs may well still trigger - but may be applying there own advance curve - or the reverse of it.

So as you surmise - this is probably what is happening to you - one way to check is with a timing light to see what the advance is doing as you raise the RPM, but its more than likely that thte CDI is the issue.

Rayman
 

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1981 CX500C US Model - Caf茅 Racer
Joined
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Discussion Starter · #11 ·
I use the DC-CDI that I use in a "special way" . I trigger them so that they fire immediately - defeating their internal advance calculation so that I can perform the advance in my controller.
Other CDIs may well still trigger - but may be applying there own advance curve - or the reverse of it.

So as you surmise - this is probably what is happening to you - one way to check is with a timing light to see what the advance is doing as you raise the RPM, but its more than likely that thte CDI is the issue.

Rayman
Thanks for confi
I use the DC-CDI that I use in a "special way" . I trigger them so that they fire immediately - defeating their internal advance calculation so that I can perform the advance in my controller.
Other CDIs may well still trigger - but may be applying there own advance curve - or the reverse of it.

So as you surmise - this is probably what is happening to you - one way to check is with a timing light to see what the advance is doing as you raise the RPM, but its more than likely that thte CDI is the issue.

Rayman
Thank you Rayman, I'll get hold of a timing light and check it out.

In other news: I'd packed some wadding into the exhausts to quieten it down for the MOT but had forgotten to remove it! So I took it out over the weekend and since then the performance has improved, I can now get about 5500 rpm just over 60 MPH.

I also found that the petcock is faulty, when I switched it over to reserve, the tank was already empty.
So I've ordered a new petcock, fuel-line & in-line filter, I'll fit them when they arrive and see whether any of that has helped.

Thanks again for your help and advice.
 
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