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Discussion Starter #1
Hi guys,

Here is my story. I bought a CX500C 1980 in parts. The bike had sit a while outdoor but it's still pretty in good shape beside some parts. One on them is the H-Box. In my hands, when I shook it, I could hear the inner tubes loose in there. I managed to cut a hole in there and I was able to get those tubes out. I welded some metal plates to close it without inner tubes (I tried, not beautiful but no leak..). I painted it flat black with exhaust paint. For the rest, freshly sonic cleaned carbs, cleaned engine, some new seals and gaskets, new plugs, new air filter.

My question is:

Since I have to pass an inspection with the bike and that it needs to have all the original parts, I'm gonna use the H-Box that way. So, what can I except in terms of performance, jetting or other stuff???? I will be running the stock air box, stock headers and the "modified" H-box with 50/50 mufflers (It's tolerated here in Montreal, Canada.)

Thanks.
 

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I don't know what the requirements are in Quebec but I'm pretty sure they don't worry about the exhaust being original as long as it isn't obnoxiously loud here in Ontario.

I've had these bikes for about 20 years now and I've never driven one with the H box in place farther than to have it safetied & back (best to have it registered & legal before making changes). From what I've read you can make a lot of changes to the exhaust without seriously impacting performance. A lot of us have bought "Quick Build" pipes to eliminate the H box (available from forum member Murrayf) and use original Harley mufflers with them (HD guys often have the dealer replace them with something louder before they take delivery so you can often get the originals for $10-15 each).
Is the MOT open in Quebec? From what I understand they are closed here.

BTW (this goes for you too makenzie71): Welcome to the forum. Please add your location to your profile and your bike's model and model year to your signature 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). It only takes a few minutes and can save a lot of time (both yours and that of people trying to help you) in the future.

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 because 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).
 

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Discussion Starter #5
I don't know what the requirements are in Quebec but I'm pretty sure they don't worry about the exhaust being original as long as it isn't obnoxiously loud here in Ontario.

I've had these bikes for about 20 years now and I've never driven one with the H box in place farther than to have it safetied & back (best to have it registered & legal before making changes). From what I've read you can make a lot of changes to the exhaust without seriously impacting performance. A lot of us have bought "Quick Build" pipes to eliminate the H box (available from forum member Murrayf) and use original Harley mufflers with them (HD guys often have the dealer replace them with something louder before they take delivery so you can often get the originals for $10-15 each).
Is the MOT open in Quebec? From what I understand they are closed here.

BTW (this goes for you too makenzie71): Welcome to the forum. Please add your location to your profile and your bike's model and model year to your signature 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). It only takes a few minutes and can save a lot of time (both yours and that of people trying to help you) in the future.

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 because 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).
Thanks for your answer, in fact, I thought my location was in my signature/profile...Anyway, I followed vigorously this forum since 2015 for any of my mods and questions. I consult a lot the Wiki and I have the FSM and also one those Haynes book. I also have the Larry's book for the carbs rebuild. I don't do anything stupid, security is important for me and I have to follow the rules since everybody here knows that I am law enforcer.

Yes, MOT office's are closed in Quebec and they will not answer my question anywhere besides the inspection site $$$$. I have to pass an inspection before I could do any modification. So, the H-box must be in place and intact.

The question is, with all the specs that I've mentioned, if everything is stock (beside the mufflers and the inner tubes in the H-Box), will it cause any problem of performance/running with the factory settings? Will I need to do avoid or do anything special??
 

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I doubt the absence of the inner pipes will make much difference and likely not at all to the sound and certainly not the appearance.

I think as long as the end product emits an acceptable volume it should be OK.

That's a guess, I don't normally refit H boxes.
 

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Discussion Starter #8
I doubt the absence of the inner pipes will make much difference and likely not at all to the sound and certainly not the appearance.

I think as long as the end product emits an acceptable volume it should be OK.

That's a guess, I don't normally refit H boxes.
Thanks, will know probably at the end of summer...I hope.🤞🏻🤞🏻
 
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