Before using this site please read the site disclaimer. Also please note that any links provided may be part of an affiliate programme (viz. eBay, Amazon) which helps support the site as I will earn a commission when visitors make a qualifying purchase.
The 1978 Honda CX500 engines made up to and including serial number CX500E-2034366 were subject to a recall to replace some components of the cam chain tensioning system to prevent failure. The recall number seems to be 40564, and the NHTSA number for the recall is 78V259000. The content of the recall notice is this:
Build Dates: 1977-07-01 to 1978-05-01
NHTSA CAMPAIGN ID Number: 78V259000
Date Owners Notified: 1978-12-19
Date Received by ODI (also the recall date): 1978-12-01
Date Added to Database: 1979-10-12
Manufacturers Involved: Honda (American Honda Motor Co.)
Component: ENGINE AND ENGINE COOLING:ENGINE
Potential Number of Units Affected: 21,591
The cam chain guide bolt may loosen due to the presence of a rubber coating on the surface of the guide in the area where the bolt seats. If the bolt becomes loose, the engine will develop a ticking noise. Continued vehicle operation with a loose guide bolt may result in breakage of the bolt and increased engine noise.
Dealer will install a cam chain guide kit to prevent loosening of the guide bolt.
Report Initiator: MFR
Vehicle Description: Motorcycles. System: Engine; Cam chain. Consequences of Defect: continued vehicle operation with a broken guide bolt could result in cam chain breakage, engine lockup, loss of vehicle control and an accident.
After the recall work was performed the dealers were supposed to punch three dots in a triangle on the engine next to the engine number. If you find a 1978 engine with the serial number in the recall range that does not have the three marks stamped into the block assume that the work hasn't been done until proven otherwise!
The cam chain parts that were involved in the replacement are below. The originals:
The updated design:
Note the additional bumps on the back of the guide and tensioner blades - this apparently isn't a functional improvement but is said to be for the ejection of the blade from the mold. The tensioner and tensioner blade are not, however, involved in the recall - that solely revolved around the guide bolt working loose. Also note the extra metal piece at the top of the guide and the extension to the plate. The updated design in the motor:
Photos of the components taken by Jimi and used with permission - many thanks Jimi, all of the early 1978 motors I have had open have had the recall performed so there have been no opportunities to get shots of these parts!
For more information on the Honda CX500 serial numbers, see this page.
In 2019 the server has had to double in capacity to support the growing site... please consider dropping the site a donation to help cover the costs! Check out our Patreon for support options, buy a shirt, buy our apps, use my NordVPN affiliate link to sign up to their service or donate via Paypal:
|Paypal $5 link ->>|
|Paypal $10 link ->>|