Honda CX 500 Forum banner
1 - 16 of 16 Posts

·
Registered
Joined
·
23 Posts
Discussion Starter · #1 ·
So a little less than a month ago, on the night my buddy and I dropped my engine out of my '82 GL500 to get it running again, the rolling frame was stolen.

The next night, my buddy told me he got the engine running again!

Now I need to put it in something...





Luckily, I have been offered a free CX500 rolling frame w bars, forks, wheels, wiring, etc.

When I pick this up, I'd like to do some customizations to the frame and seat to achieve a chopper style.

Additionally, I have no idea what I'm in store for yet with dropping the GL engine in it. I was told that there are a few minor things I need to change on the engine itself?



I hope that you guys may have a lot to offer, and I'll keep this thread updated a the project progresses.

I'm not trying to make an extremely beautiful show-bike. I want something original, safe, and most of all: Mine!
 

·
Super Moderator
Joined
·
15,413 Posts
Well the cx frame could be interesting. The gl500 engine should work fine but you will probably have to rework the front engine brackets so they fit on the frame in a way that you can modify them to work. Everything else should be easier but the engine will need cx carbs and manifolds to fit in the frame. The gl ones wont work because it's to tight.



Then you will need all the gl electrical parts and you're good to go.
 

·
Premium Member
Joined
·
2,510 Posts
What year is the CX500? If it is 1982 almost no changes will be needed to install a GL500 engine.



It will be more involved for other years but it has been done before.
 

·
Registered
Joined
·
1,151 Posts
I am curious as to how this turns out for you. I am working on getting a 81 gl500 motor into a 79 cx frame. Is the exhaust from the cx or the gl? I tried using the gl's h-pipe on the cx and the rear mounts are spaced differently. Also the cx coolant reserve didn't fit in the stock location because the back of the motor is a little longer or closer to where the tank should be. The pigtails for the stator is not going to match the connections on the cx frame. You will have to do some rewiring but you can find wiring diagrams to change that. You should be able to get those from members on this forum.
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #5 ·
I am currently waiting on an email response from my connection giving me the bike in response to the year of the bike and the condition.

The engine is in the bike, but I have no idea what condition it's in yet. I'm planning on using my engine with the CX carbs as seems to be common consensus.



As far as the exhaust, I probably wont be using the exhaust form my GL, as I want to drop the frame an inch or two and there would be no room for the collection box.

I'll have to just build some custom exhaust, which I've heard is the easiest part of building a junker.



I'll let you guys know as soon as I get more details, and when I find a friend and a truck, I'll get the bike and post up some pics.

Thanks again for the help, guys!
 

·
Registered
Joined
·
96 Posts
I bought a project last summer that a guy started and then couldn't finish for several reasons--a '78 CX500C with an '82 GL500 engine. He had gotten no farther than hanging the engine in the frame when he quit, because of the aforementioned issue with the wiring and the overflow tank. I haven't actually done anything with it, but I've been looking it over, and maybe the easiest way to fix those problems would be to get the rear cover, electrics, and flywheel from a CDI bike and convert back. I'm not sure about the ignition advancer, there may be some hidden issue there to keep this from being that easy. Further, the '82 engine does not have a place for the midplate engine hangers to bolt on; they're on the rear cover on the earlier bikes. With a chopper/bobber in mind you may not care; a cafe-style bike may need them to keep the frame from flexing. Honda wouldn't have spent to money to put them on every CX500 if they didn't think they were important. With the two-piece cast iron mounts used on GL500/650s and CX650s they're apparently not needed.

Because of that change in front motor mount design, the top radiator hose on a GL500 and a 650 comes out of the middle of the top tank instead of the left side like a CX500, so you need the radiator, curved hose and angled thermostat housing from a CX500. Otherwise, the wishbone front mount for the CX fits the GL500 engine perfectly; I don't know whether GL500 mounts would work on a CX frame. I know CX650C mounts will not line up with the holes in the frame spine (dangit, I have a spare 650 engine...), but I don't know if GL500 mounts have the same frame bolt spacing as a 650. I would actually bet they're the same as the CX500 since the castings have to be different between the 500 and 650, but they may not be.
 

·
Registered
Joined
·
27 Posts
I have a 1983 CX 650c frame with a GL 650 motor in it. It fits like a glove. I hard tailed mine and it dropped abou 6 inches. The only issue I had was that the coolant res. won't fit as stock. Either will the stock h-box. Neither is aproblem since I am going custom with mine. Here are some pics. Enjoy. Remeber with imagination and a welder.....anything is possible!
 

Attachments

·
Registered
Joined
·
1,151 Posts
When I bolted my gl motor in all the bolt holes matched up fine. The mounting plates that bolt under the tank and mount just behind and in the middle behind the heads I didn't use. I felt the front wishbone and the four rear mounting points would be enough to keep it from flexing more than normal.
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #9 ·
Alright, he finally replied.

Im going to be putting my 82 GL500 engine in a 79 CX500 frame.

He does not have the title.



Complete(?) broken CX engine (for parts), with most everything else included.

Total costs so far:

$100 - Bonded Title





So i can take the parts that aren't going to fit on the CX frame and switch them with the CX engine parts, which will hopefully be salvageable. Seems like a pretty killer deal so far.

Still, I'm waiting on a friend and a truck, and then this can all be final.



I think I'll be a little better about not leaving a rolling frame in the street overnight this time around.
 

·
Super Moderator
Joined
·
15,413 Posts
I have a 1983 CX 650c frame with a GL 650 motor in it. It fits like a glove. I hard tailed mine and it dropped abou 6 inches. The only issue I had was that the coolant res. won't fit as stock. Either will the stock h-box. Neither is aproblem since I am going custom with mine. Here are some pics. Enjoy. Remeber with imagination and a welder.....anything is possible!




Your case doesn't exactly make a big difference.



if I remember right the only difference between a cx650 and gl650 engine is the output shaft.
 

·
Registered
Joined
·
96 Posts
Yes, I would expect that the 650 mounts would accept any 650 engine. Not to hijack the thread, but where the problem lies is trying to sling a 650 engine into a 500 frame. Just FYI, CX650C engine hangers have the wrong angle at the two frame holes, because the spine of a Custom is at a different angle than the standard CX500. Presumably to get the nose in the air for that "custom" stance. I see a pair of Canadian CX650E hangers on ebay, and those holes look closer to a CX500 frame angle. Just don't know about the spacing. Also I see a pair of GL500 hangers and, while they're two-piece, they're not cast iron. Just stamped steel like the other 500 hangers.
 

·
Registered
Joined
·
27 Posts
Your case doesn't exactly make a big difference.



if I remember right the only difference between a cx650 and gl650 engine is the output shaft.




Believe it or not the CX650c Drive shaft mated up to the gl 650 motor. I kept the gl shaft just in case, but it was never needed.
 

·
Registered
Joined
·
27 Posts
My conversion went smooth because I used a crashed gl650 as a parts bike. Wire harness, motor and all. I put all that stuff in a cx650c rolling frame
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #14 ·
Alright, so when my buddy told me my engine was running, he forgot to mention the block is cracked. So yeah, Im scrapping this engine and another for maybe $200.



The question now is.... I'm going to take the '81 CX500 rolling frame, buy a brand new crate engine, weld on some mounts where needed, and make a running bike.



So what I need help with now is figuring out what kind of engine to get. I know I need an engine with right side shaft, and that to keep the bike center-balanced, that shaft will have to be positioned in a manner close to the CX or GL engine.



Has anyone every thrown another engine in a GL or CX frame before?
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #15 ·
Alright, so when my buddy told me my engine was running, he forgot to mention the block is cracked. So yeah, Im scrapping this engine and another for maybe $200.



The question now is.... I'm going to take the '81 CX500 rolling frame, buy a brand new crate engine, weld on some mounts where needed, and make a running bike.



So what I need help with now is figuring out what kind of engine to get. I know I need an engine with right side shaft, and that to keep the bike center-balanced, that shaft will have to be positioned in a manner close to the CX or GL engine.



Has anyone every thrown another engine in a GL or CX frame before?


I also want to keep it 500-750cc.
 

·
Registered
Joined
·
192 Posts
I bought a project last summer that a guy started and then couldn't finish for several reasons--a '78 CX500C with an '82 GL500 engine. He had gotten no farther than hanging the engine in the frame when he quit, because of the aforementioned issue with the wiring and the overflow tank. I haven't actually done anything with it, but I've been looking it over, and maybe the easiest way to fix those problems would be to get the rear cover, electrics, and flywheel from a CDI bike and convert back. I'm not sure about the ignition advancer, there may be some hidden issue there to keep this from being that easy. Further, the '82 engine does not have a place for the midplate engine hangers to bolt on; they're on the rear cover on the earlier bikes. With a chopper/bobber in mind you may not care; a cafe-style bike may need them to keep the frame from flexing. Honda wouldn't have spent to money to put them on every CX500 if they didn't think they were important. With the two-piece cast iron mounts used on GL500/650s and CX650s they're apparently not needed.

Because of that change in front motor mount design, the top radiator hose on a GL500 and a 650 comes out of the middle of the top tank instead of the left side like a CX500, so you need the radiator, curved hose and angled thermostat housing from a CX500. Otherwise, the wishbone front mount for the CX fits the GL500 engine perfectly; I don't know whether GL500 mounts would work on a CX frame. I know CX650C mounts will not line up with the holes in the frame spine (dangit, I have a spare 650 engine...), but I don't know if GL500 mounts have the same frame bolt spacing as a 650. I would actually bet they're the same as the CX500 since the castings have to be different between the 500 and 650, but they may not be.
The front GL mount does not work with the CX frame. The CX front mount is overbuilt and can have the large tube cut off which makes fitment easier. Remember that the GL does not have a cross over tube on the front mount as the engine serves that purpose. The rear brackets are not needed or Honda would have left them on the GL which is a heavier bike. I converted a CX motor to a GL just to get around the CDI issues. For the conversion you need the wiring harness, ignitors and voltage regulator. My bike had the GL motor in it and then the CX motor with the GL rear case. Both were bolt on affairs.
 
1 - 16 of 16 Posts
Top