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78 cx500 Rusty barn find edition
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Discussion Starter · #1 · (Edited)
Hey all, just joined this forum a few days back (tons of great info and knowledgeable people by the way).
Anyway I pulled a 78 cx out of a barn last year that'd been there since presumably about 2013-14. Finally started really digging into it this year and after removing the carbs for a good cleaning, I stumbled upon a decent amount of aluminum oxide inside of the intake. Not so much the little manifolds that have the carb boots but the intake inside of the head. Will post some pictures when I get off work in a few hours but I am curious as to how much of a problem this may or may not be.
Any help appreciated.
Thanks, Dave
Update - First photo is right side, second is left
Wood Automotive tire Sculpture Font Snout

Automotive tire Wood Gas Automotive wheel system Auto part
 

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'84 CX650E that is evolving into a GL500
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It's hard to say without seeing so I'll wait for the pics before commenting.

Welcome to the forum. Please add your location and your bike's model and model year 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 may or may not have had all of 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. If it has been sitting that long you don't need to check the date codes on your tires to know that they are over 5 years old and should be replaced 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 (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).
 

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Registered
78 cx500 Rusty barn find edition
Joined
·
3 Posts
Discussion Starter · #3 ·
Hey all, just joined this forum a few days back (tons of great info and knowledgeable people by the way).
Anyway I pulled a 78 cx out of a barn last year that'd been there since presumably about 2013-14. Finally started really digging into it this year and after removing the carbs for a good cleaning, I stumbled upon a decent amount of aluminum oxide inside of the intake. Not so much the little manifolds that have the carb boots but the intake inside of the head. Will post some pictures when I get off work in a few hours but I am curious as to how much of a problem this may or may not be.
Any help appreciated.
Thanks, Dave
It's hard to say without seeing so I'll wait for the pics before commenting.

Welcome to the forum. Please add your location and your bike's model and model year 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 may or may not have had all of 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. If it has been sitting that long you don't need to check the date codes on your tires to know that they are over 5 years old and should be replaced 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 (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).
Will definitely update my profile for sure 🙂 I appreciate all the tips, I don't know too much about these street beasts as I do off road. Pics posted btw🤙
 

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As long as the valve and seat aren't corroded. You could run kero down there with the piston at TDC on the compression stroke and see if it leaks.

Or better still, do a leak down test.

Was this stored with no carbs fitted?
 

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78 cx500 Rusty barn find edition
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3 Posts
Discussion Starter · #5 ·
As long as the valve and seat aren't corroded. You could run kero down there with the piston at TDC on the compression stroke and see if it leaks.

Or better still, do a leak down test.

Was this stored with no carbs fitted?
It honestly doesn't look too bad and I may be over worried, looks like just the aluminum walls of the intake have a bit of surface corrosion that seems to wipe away but I'll have to test it to make sure. And no actually, the bike was owned by an older gentleman and only has 6700 miles on it. Everything was there and on it when I bought it... Assume the poor thing was driven to it's resting place.
 
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