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'80 CX500 C German 1G I think
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Discussion Starter · #1 ·
Hey all, I recently purchased a 1980 cx500c (that hasn’t run in probably 20 years) that I am looking to rebuild/build into a cafe racer. I have some experience working on newer motorcycles but this is my first antique, so to speak, and by far my most intensive build yet. Just looking to see if there is anyone in the Atlanta area that has a cx500 and wouldn’t mind giving me some pointers or meeting up for lunch to show me their bike. Let me know.
 

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'84 CX650E that is evolving into a GL500
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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.
 

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100% agree with SidecarBob's comment.

My version is ...
  • First make the engine work (carbs, valves, etc.)
  • Then make it roadworthy (tires, lights, brakes, etc.)
  • Finally, make it look the way you want it.

And please don't chop anything off the frame until you're ready to commit.

Enjoy.
 

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'80 CX500 C German 1G I think
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Discussion Starter · #4 ·
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.
100% agree with SidecarBob's comment.

My version is ...
  • First make the engine work (carbs, valves, etc.)
  • Then make it roadworthy (tires, lights, brakes, etc.)
  • Finally, make it look the way you want it.

And please don't chop anything off the frame until you're ready to commit.

Enjoy.
Thank yall that's exactly what I was thinking, I just did my first test start yesterday, unsuccessfully. I have fresh spark plugs, fresh oil and a fresh battery. The bike seems to have compression and it is turning over but the fuel is not getting down the fuel line and in/through the carbs. The petcock is a non-vacuum version and it will release fuel when the fuel line is not hooked up but as soon as I connect the fuel line, no fuel will go down. I imagine this means that the carbs need to be serviced so I am planning to pull them out and order Larry's book.
 

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'84 CX650E that is evolving into a GL500
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Just to clarify, you man that fuel isn't getting to the float bowls, not that the fuel line itself is blocked, right? If so a thorough cleaning of the carbs is probably what you need.
 

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'80 CX500 C German 1G I think
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Discussion Starter · #6 ·
Just to clarify, you man that fuel isn't getting to the float bowls, not that the fuel line itself is blocked, right? If so a thorough cleaning of the carbs is probably what you need.
The fuel line does not appear to have any blockages but fuel is not going into the lines when I connect them to the petcock. When no lines are connected to the petcock fuel flows out normally. So no fuel is getting to the carbs either way and I think that fuel intake to the carb would be the only prevention of fuel flow. I have never had a carburated bike before so I don't exactly know technical terms or how they work fully.
 

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The fuel line does not appear to have any blockages but fuel is not going into the lines when I connect them to the petcock. When no lines are connected to the petcock fuel flows out normally.
How do you know that fuel is not going into the line? Do you have clear fuel lines?

Fuel will not flow through the fuel line if the float bowl is already full.

With the petcock in the open position, place a container under the bowl drain line and open the bowl drain screw. Does fuel flow out?
 

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'84 CX650E that is evolving into a GL500
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Good point^^

When you said "lines" I wondered if you had a vacuum petcock (they have 3 lines but fuel in only 1 of them).
If you disconnect both ends of the fuel line you should be able to blow through it to make sure it isn't blocked.

When gasoline evaporates it leaves behind varnish. It is pretty common for the varnish to glue the float valve's needle into the seat so that when the petcock is turned on it can't get into the carb and if that happens in one carb it isn't a big stretch for it to happen in both.

BTW: Why do you think it is German and what does "1G" mean?
 

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'80 CX500 C German 1G I think
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Discussion Starter · #11 ·
How do you know that fuel is not going into the line? Do you have clear fuel lines?

Fuel will not flow through the fuel line if the float bowl is already full.

With the petcock in the open position, place a container under the bowl drain line and open the bowl drain screw. Does fuel flow out?
I put in a clear fuel filter so I could see if fuel was flowing through. Will try to check the bowl drain in a few.
 

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'80 CX500 C German 1G I think
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Discussion Starter · #12 ·
Good point^^

When you said "lines" I wondered if you had a vacuum petcock (they have 3 lines but fuel in only 1 of them).
If you disconnect both ends of the fuel line you should be able to blow through it to make sure it isn't blocked.

When gasoline evaporates it leaves behind varnish. It is pretty common for the varnish to glue the float valve's needle into the seat so that when the petcock is turned on it can't get into the carb and if that happens in one carb it isn't a big stretch for it to happen in both.

BTW: Why do you think it is German and what does "1G" mean?
I believe my bike is from Germany because the speedo is in Km, it has German wording on the serial number plate and there are stickers on the bike in German. Also when I used the serial number decoder it said that there is a German 1G "full power" edition bike and my serial numbers match up with that so I just assumed that is what my bike is. I am not sure what exactly that means or if it has any differences from the other models of 1980 cx500 customs. I put the german title in there to see if any of the cx experts would be able to tell me any potential differences later down the road.

Also, no I do not have a vacuum petcock.
 

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For these test starts I would use an auxiliary tank to eliminate the petcock altogether.

Also, if it has been sitting for 20 years, there is a 99.99999% chance you will need to take the carbs apart, remove varnish, replace dried rubber bits, clean out the small passages and jets with an ultrasonic cleaner, etc.

If it starts and runs reliably without servicing the carbs, then go buy a lottery ticket. Or don't bother because you've already used a lifetime's supply of good karma
 

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'84 CX650E that is evolving into a GL500
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Yep. That sounds like it could just be from Germany. The "1G full power" must refer to the engine being allowed to develop the power the designers intended instead of being restricted to lower power for riders with lower license classes.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Probably brought home by a US service member stationed in Germany in the '80s. From what I've read about vehicle importing, it used to be a lot easier than it is now.
 

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'84 CX650E that is evolving into a GL500
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Either that or brought with someone that immigrated.
At one time having a model made for a foreign market could be problematic but these days with the internet in every home it's fairly easy to find the information you need.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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If it's so simple, I need to visit my nephew in the UK and score a 500E!
From what I've read, a vehicle built to foreign emissions standards requires expensive upgrades performed by a small number of certified companies to be imported. ItchyBoots had to abandon her India-spec Himalayan when she reached the Netherlands for that very reason. (Her local RE dealer traded her a new one for it to use as a static display.)
Maybe there's an exemption for older vehicles, but I didn't see it clearly stated.
 

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'84 CX650E that is evolving into a GL500
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Things may have changed because of those emissions regs but I understand that in the '80s immigrants to Canada were allowed to bring vehicles with them for their own personal use (something called "settler's effects" IIRC) and I'd be surprised if things were much different in the US.

Anyway, I meant that owning one of the ones that were imported when it was easier to do so is easier now than it was when they were imported.

FWIW, someone imported a couple of hundred Dneprs into Canada in the early '90s. They had long since gone out of business by the time I got mine a decade or so later so the only information available was what was in the Owner's Manual (fortunately well translated and more like a shop manual). But even with a good reference book there were no dealers or parts warehouse.
I heard a rumour that a new Lada dealer in the Niagara area had received the wrong shipment of parts from Soviet Autoexport a couple of weeks before and I spent a whole Saturday making long distance calls to try to track them down only to be told that they had been sent to the US from someone who didn't know who to contact there (this was also long before Ural America).
And that's for a model that was brought into the country in bulk by an authorized importer. Imagine what it would have been like to find parts & info for a single example of a model imported by an individual in those days.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Imagine what it would have been like to find parts & info for a single example of a model imported by an individual in those days.
I think you'd want good machining skills.
 

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Randall, I had no issues registering in Connecticut the two CX650Es I "imported" from Canada some years ago. I'm pretty sure the Es don't exactly meet US DOT requirements, but in those cases the close similarities between model names, CX650C (US) and CX650E (CN) may have let it through without them searching the DOT approved list too closely, I dunno. Some Californian members have paid dearly to have CX650Es imported through a broker as I recall, again years ago. It may also help that CT does not title older vehicles, perhaps the titling process if it were applicable would dictate a closer scrutiny. :unsure:
 
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