Honda CX 500 Forum banner

1 - 15 of 15 Posts

·
Registered
'80 CX500C
Joined
·
7 Posts
Discussion Starter · #1 ·
Hey guys, just bought my first CX - a 1980 custom.

I've had a read-through found a link to Larry's book. While I'm waiting for that one to arrive I've got a question about side air valves. The one in my kit does not have a bulb of the original (see below)- will this affect the performance?
208235
 

·
Super Moderator
'84 CX650E that is evolving into a GL500
Joined
·
16,291 Posts
BTW: Those are the air cut valves (sometimes called air cutoff). Learn what they do and why you don't really need them here

BTW: Welcome to the forum. Please add your location and your bike's model and model year (NOT year first registered if that's what the paperwork shows) to your profile 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).

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).
 

·
Registered
'80 CX500C
Joined
·
7 Posts
Discussion Starter · #5 ·
BTW: Those are the air cut valves (sometimes called air cutoff). Learn what they do and why you don't really need them here

BTW: Welcome to the forum. Please add your location and your bike's model and model year (NOT year first registered if that's what the paperwork shows) to your profile 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).

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).
Thanks Bob. I already learned about replacing rubber parts the hard way! I'll make those changes to my profile
 

·
Registered
Joined
·
1,578 Posts
Hey welcome.
You might of posted an intro somewhere else....(and I missed it)
Hopefully that Melb lock-down will end soon....and bikes can get back on the road.


good luck with the project
 

·
Registered
Joined
·
2 Posts
Hey guys, just bought my first CX - a 1980 custom.

I've had a read-through found a link to Larry's book. While I'm waiting for that one to arrive I've got a question about side air valves. The one in my kit does not have a bulb of the original (see below)- will this affect the performance? View attachment 208235
What is this “Larry’s book” of which you speak?
 

·
Premium Member
1982 CX500C (US)
Joined
·
175 Posts
Most of the cheap eBay kits include the wrong ACV diaphragms (without the bulb) for the CX500

208350
 

·
Registered
1978 CX500 "The Grub", '83 GL650, '82 GL500 Project "AdventureWing", '79 CX500C, '78 CX500 Scrambler
Joined
·
10,417 Posts
In other places, Bob, you've argued that if Honda included something, it's there for a reason. Why should the ACV be any different? Why would Honda have added such complexity if it's unnecessary?
 

·
Super Moderator
'84 CX650E that is evolving into a GL500
Joined
·
16,291 Posts
Because of the overly lean mixtures necessitated by emissions regulations of the time. Have you read Mike's article about bypassing them? I figure if someone who has written several books on rebuilding Keihin carbs recommends it they are no longer needed.

I have also described how some things like the throttle return cable and the GL1000's "reserve lighting unit" should be eliminated because they cause more problems than they prevented. The air cuts fall into the same category.
 
1 - 15 of 15 Posts
Top