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1980 CX500 Deluxe
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Discussion Starter · #1 ·
I've been looking for a bike like this for a while. My father, RIP 6 years, had one similar when I was a kid but I don't know exactly what he had and my mom doesn't remember either. Anyway, found one that runs but is ugly for $850. Going to have a couple title issues that hopefully can get resolved. The previous owner is cool with helping me get that sorted out. Current plan is to mostly restore it on the cheap. And who knows, maybe in a couple years I'll do the cafe racer route, still on the fence about it. Seems to be a coolant leak, possibly mechanical seal? Right muffler is damaged right under foot pedal, no lights up front since it had a wind fairing that was removed, it's broken probably from minor accident or being tipped over but that took the brunt of the hit. It came with the old headlight and turn signals and I wanted those on anyway. Carbs need cleaned, and possible overflow pipe thing is cracked, I guess that's common but fixable? And of course, a lot of cosmetic TLC. Anyway, I'm excited to have found a specific forum that seems very active as this is my first bike and I'm trying to learn a lot about it. A good friend of mine is doing the cafe racer route on his, so I already have a new seat lined up for $40.
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Welcome to the forum.
Enjoy your CX experience.
(One of the moderators here posts extensive starting advice....so I'll leave that to S/Bob)
 

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‘81 CX500B, ‘02 W650
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Hey man- good luck with the journey, I’m sure that’ll clean up nicely. The regulars here really know their stuff so it’s a great place to be!
 

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well, if it runs and the tank doesn't leak, then that's a good start.

Coolant leak is likely from either the weep hole near the water pump or one of the connection points for the coolant pipes. If the former, then you'll probably need a new mechanical seal. If the latter, then new o-rings on the connections. Both are doable, but the mech seal is usually the bigger job. Lots of info here and at motofaction
 

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'84 CX650E that is evolving into a GL500
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Nothing wrong with the seat that's on it if you only take it out on dry days ;-) ;-)

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). It looks like your bike still has the original rubber brake line, which should have been replaced every 2 or 3 fluid changes (= 5 or 6 years) so I recommend shopping for modern stainless braided ones (they last practically forever and double the life of the fluid) and installing them when you rebuild the brakes (you should always rebuild the brakes with new rubber parts if you don't know when it was last done). 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 (this sounds a lot like your plan) 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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1980 CX500 Deluxe
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Discussion Starter · #6 ·
Nothing wrong with the seat that's on it if you only take it out on dry days ;-) ;-)

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). It looks like your bike still has the original rubber brake line, which should have been replaced every 2 or 3 fluid changes (= 5 or 6 years) so I recommend shopping for modern stainless braided ones (they last practically forever and double the life of the fluid) and installing them when you rebuild the brakes (you should always rebuild the brakes with new rubber parts if you don't know when it was last done). 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 (this sounds a lot like your plan) 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.
Thank you very much for your reply! I did purchase a used clymer book, it has the color wiring diagrams since my wiring up front is a mess from the wind fairing. Yeah, I definitely plan on mostly restoring it and enjoying it for a few years, I may or may not end up modding it. I purchased a new master cylinder, this one was corroded on the reservoir and the cylinder piston is seized, I didn't think about the brake line so I'll get one of those. I got new boots for the front caliper, it doesn't look like it's in bad shape except the rubber parts so I'll rebuild it. To echo your thoughts, my plan was to go through the whole service manual and service all parts but I'll take special care to not half ass it. Also, I'm pretty sure my mechanical seal needs replaced since I see coolant has past leaked from the weep hole, not sure if I will do the actual fix or the Shep workaround fix I've seen on here. And I'm sure that my right float bowl overflow pipe is cracked, it leaks after running for not very long, and it seems like Larry has a cool article on that in the wiki. I'm just grateful to be part of a community that seems to really want to help and is knowledgeable on this bike in particular. Anyway, thank you again for the advice, it's much needed where I am still very new to motorcycles.
 

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'84 CX650E that is evolving into a GL500
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Re manuals: The Clymer is better than nothing, the Haynes is somewhat better but for this family of bikes the Factory Service Manuals are the best. FSMs are written for professional mechanics to use and are often next to impossible to understand if you aren't factory trained but whoever wrote the ones for the CX/GL500/650 family managed to provide all of the needed information in a way that just about anyone can understand and actually organized it in a way that makes sense (I wish the book for my GoldWing was so well laid out).

Re caliper: You should replace the rubber piston seals as well as the boots. As the seals age they get harder and can cause the brake to drag.

Re mechanical seal: From the beginning of production to the bore that the mechanical seal is pressed into was 27.8mm diameter but some time in '81 they changed that to 28.3mm. The seal for the smaller bore has not been available for a long time and many of the larger ones have been ruined by people trying to install them in earlier engines.
The book says to remove the engine from the frame and remove the rear cover to press in a new seal. For several years the only way to replace the seal in earlier engines (like yours) involved taking the rear cover off and enlarging the bore, generally either taking it to a machine shop or doing it at home with a flap wheel in a drill (drill press preferred).
Forum member Shep initially came up with a way to press a seal in with the engine in the frame. Shortly after that he figured out that if the seal's cup was left in the engine a new seal could be removed from its cup and glued into the old seal's cup and it didn't take long for someone to realize that the insides from the later seal would fit into the smaller cup, eliminating the need to modify the bore.

Re carb: There are several potential causes for the kind of leak you describe, including
  • Loose drain screw or debris between the screw and its seat preventing it from sealing correctly. Not the most common cause but it can happen (especially if the carbs were drained for storage and someone forgot to tighten one of the screws) and it is easy one to check.
  • Debris or dried fuel varnish between the float valve's needle and seat preventing it from closing properly. This is by far the most common cause of fuel coming out of the drain line. You can often fix this by turning the fuel off, draining the float bowl, giving the float bowl a couple of sharp raps with the handle of the screwdriver, turning the petcock back on and then tightening the drain screw.
If that doesn't work a couple of quick blasts of air (20 PSI max) into the fuel line can move the blockage but make sure you have a container under the drain lines.
If the valve still doesn't seal you may have to remove the bowl, take out the float's pivot pin and clean the needle and seat (methyl hydrate on a cotton swab works well for this)(methyl hydrate, AKA methanol is one of the basic solvents every shop should have - buy it by the gallon in the paint dept. where it is sold for thinning shellac).
  • a stuck or incorrectly adjusted float that is not closing the float valve
  • crack in the overflow tube (possible but less likely than the above)
(there may be others that don't come to mind at the moment)

Are you planning to restore it to original condition or just restore it to good working condition? If you aren't trying for original there are aftermarket headlights & mounts that might make the job easier.
You may find that most of the headlight assembly in the fairing is made up of parts from the bike's original headlight (Vetter did that most of the time) and if you manage to get a Honda headlight shell from about when the bike was made those parts might fit it.
The original front turn signals have 2 filament bulbs (similar to the tail/brake light bulb) with the dim filaments for marker lights and the bright ones for signals and the turn signal switch turns the marker off when the signal is flashing. Maintaining all original lighting functions is a legal requirement (not to mention that marker lights make you more noticeable to other road users) so it is a good idea to either use signals that are designed for that (they usually have 3 wires but not all 3 wire signals will work as markers) or to add separate marker lights (note that the turn signals must be a minimum of 4" from any other light that is on when they are flashing - a good requirement because if they are too close it is hard to tell if they are flashing)(Yes, that mans that those hadlights with LED signals built in are NOT legal)
 

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1980 CX500 Deluxe
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Discussion Starter · #8 ·
Re manuals: The Clymer is better than nothing, the Haynes is somewhat better but for this family of bikes the Factory Service Manuals are the best. FSMs are written for professional mechanics to use and are often next to impossible to understand if you aren't factory trained but whoever wrote the ones for the CX/GL500/650 family managed to provide all of the needed information in a way that just about anyone can understand and actually organized it in a way that makes sense (I wish the book for my GoldWing was so well laid out).

Re caliper: You should replace the rubber piston seals as well as the boots. As the seals age they get harder and can cause the brake to drag.

Re mechanical seal: From the beginning of production to the bore that the mechanical seal is pressed into was 27.8mm diameter but some time in '81 they changed that to 28.3mm. The seal for the smaller bore has not been available for a long time and many of the larger ones have been ruined by people trying to install them in earlier engines.
The book says to remove the engine from the frame and remove the rear cover to press in a new seal. For several years the only way to replace the seal in earlier engines (like yours) involved taking the rear cover off and enlarging the bore, generally either taking it to a machine shop or doing it at home with a flap wheel in a drill (drill press preferred).
Forum member Shep initially came up with a way to press a seal in with the engine in the frame. Shortly after that he figured out that if the seal's cup was left in the engine a new seal could be removed from its cup and glued into the old seal's cup and it didn't take long for someone to realize that the insides from the later seal would fit into the smaller cup, eliminating the need to modify the bore.

Re carb: There are several potential causes for the kind of leak you describe, including
  • Loose drain screw or debris between the screw and its seat preventing it from sealing correctly. Not the most common cause but it can happen (especially if the carbs were drained for storage and someone forgot to tighten one of the screws) and it is easy one to check.
  • Debris or dried fuel varnish between the float valve's needle and seat preventing it from closing properly. This is by far the most common cause of fuel coming out of the drain line. You can often fix this by turning the fuel off, draining the float bowl, giving the float bowl a couple of sharp raps with the handle of the screwdriver, turning the petcock back on and then tightening the drain screw.
If that doesn't work a couple of quick blasts of air (20 PSI max) into the fuel line can move the blockage but make sure you have a container under the drain lines.
If the valve still doesn't seal you may have to remove the bowl, take out the float's pivot pin and clean the needle and seat (methyl hydrate on a cotton swab works well for this)(methyl hydrate, AKA methanol is one of the basic solvents every shop should have - buy it by the gallon in the paint dept. where it is sold for thinning shellac).
  • a stuck or incorrectly adjusted float that is not closing the float valve
  • crack in the overflow tube (possible but less likely than the above)
(there may be others that don't come to mind at the moment)

Are you planning to restore it to original condition or just restore it to good working condition? If you aren't trying for original there are aftermarket headlights & mounts that might make the job easier.
You may find that most of the headlight assembly in the fairing is made up of parts from the bike's original headlight (Vetter did that most of the time) and if you manage to get a Honda headlight shell from about when the bike was made those parts might fit it.
The original front turn signals have 2 filament bulbs (similar to the tail/brake light bulb) with the dim filaments for marker lights and the bright ones for signals and the turn signal switch turns the marker off when the signal is flashing. Maintaining all original lighting functions is a legal requirement (not to mention that marker lights make you more noticeable to other road users) so it is a good idea to either use signals that are designed for that (they usually have 3 wires but not all 3 wire signals will work as markers) or to add separate marker lights (note that the turn signals must be a minimum of 4" from any other light that is on when they are flashing - a good requirement because if they are too close it is hard to tell if they are flashing)(Yes, that mans that those hadlights with LED signals built in are NOT legal)
The caliper rebuild kit I got came with the piston boots and the piston seal. I just pulled everything apart and cleaned it well, it doesn't look too bad. I'm sure it will work well after new seals, lube, and boots are on.

Sounds like I will be doing the Shep method of putting in the new mechanical seal guts in the old cup.

I will probably take the carbs off and open them up, I want to visually inspect it and I have new intake manifolds to put on anyway.

Luckily, this bike came with a box that has the original headlight and turn signals. I figured out the wiring enough to take off the old fairing wiring harness and connect the stock headlight and turn signals, they do indeed work so I took them apart and cleaned them up since they was quite a bit of pitting and rust. They cleaned up surprisingly well, I'll just need to go over it again with some rust remover or diet coke like some people use, and then apply a wax to keep it from rusting.

I'm not looking to make this bike look completely original, I want it functional and I'm definitely willing to modify some parts to make it so, while still keeping it looking close to how it did in 1980. The big difference will be that a friend of mine is fantastic with plastidip, so I'll be doing that on the original painted body parts since the original paint is very sun damaged and worn.

It's funny you mention those dumb, small, illegal LED turn signals. I almost hit a biker at a 4 way stop last year. I thought we were both going straight and it wasn't until he almost hit my car while he was making a left turn that I saw the tiny little LED blinker. He threw up his hands all pissed off and I was very frustrated. I don't plan on being that type of driver.
 

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'84 CX650E that is evolving into a GL500
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How well does Plasti Dip hold up to gasoline? You need to do the tank with something that won't dissolve when you spill gas on it (no matter how careful you are it will happen eventually).
I told this in another thread recently: Some years ago a friend of mine used car touch up paint in spray cans to re-paint his bike. A few weeks later the nozzle's trigger stuck when he was filling it and he almost cried as he watched his new paint wash off.

I've had good results in the past using engine enamel in rattle cans on gas tanks and other body parts. It won't hold up as well as a good acrylic or urethane automotive paint but if you don't have a gun & compressor it could be the best bet.
I have also had decent results using urethane based rust paint but it isn't as glossy.
 

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If you still have your brake cylinders apart scrape the seal grooves out clean. If the old crusty deposits are not removed the seals will not seat deep enough and: #1 make it more difficult to insert the pistons and #2 cause extra drag on the piston.
 
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1980 CX500 Deluxe
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Discussion Starter · #11 ·
How well does Plasti Dip hold up to gasoline? You need to do the tank with something that won't dissolve when you spill gas on it (no matter how careful you are it will happen eventually).
I told this in another thread recently: Some years ago a friend of mine used car touch up paint in spray cans to re-paint his bike. A few weeks later the nozzle's trigger stuck when he was filling it and he almost cried as he watched his new paint wash off.

I've had good results in the past using engine enamel in rattle cans on gas tanks and other body parts. It won't hold up as well as a good acrylic or urethane automotive paint but if you don't have a gun & compressor it could be the best bet.
I have also had decent results using urethane based rust paint but it isn't as glossy.
My friend is great with plastidip, and he can do it on the cheap over and over again if it gets ruined. He changes the way his bike looks every other year with plastidip, probably because the gas ruins it lol.

If you still have your brake cylinders apart scrape the seal grooves out clean. If the old crusty deposits are not removed the seals will not seat deep enough and: #1 make it more difficult to insert the pistons and #2 cause extra drag on the piston.
Hey! Thanks for that tip, Im not sure I paid enough attention to that and I haven't put it together yet so I'll make sure to clean it out better.
 
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