Cam Chain Master Link Fail

[Steverinomeiste]

I had a little setback today. I was warming my bike up and had it at a medium fast idle and then suddenly I heard the sound of the cam chain coming loose. And it sounds exactly like you would imagine it sounds like. I have had this engine apart so many times now I felt kind of like an expert this time, not needing a manual and having the right tools, including my little home made flywheel puller. Anyway, I should of known better than to reuse the master link, but I did. Fortunately I don't think there is any damage. This is a free running engine isn't it?
Steve

[Larzfromarz]

I can sympathize completely with a similar problem...

[Erik S]

I just had to remove and replace the cam chain using the old master link, should I get a new link? This is the first I've heard here about using a new one. Have not started the engine yet.

[Steverinomeiste]

Hi Erik S
I think I might of picked up that rule in shop when I was a kid. I think the flat surfaces and square edges of the retainer clip and the slots in the link pin get rounded off from repeated installation and removal. The wear allows them to slip away from their seated position under load. I can definately tell a new retainer clip from a old one. So now why didn't I replace the thing if I knew better?

[Larzfromarz]

In principle I would whole heartedly agree with Steve. In practice it may be another thing. I have used the "old" retainer in this case to expedite the repair. If installed properly and not abused in removal and installation my feelings are you should be ok. If you happen to have hen's teeth on the shelf then by all means replace. My thinking would also be to look at the miles on the engine and just replace the entire cam chain assembly. In my case there are less than 5k miles and the chain should only be minimally stretched so I'm keeping it. My problem was I missed the teeth on the crank end and caused contact with the retainer and crank and broke the clip. I actually considered drilling and safety wiring the master link with .021 ss wire but robbed a retainer from a spare engine.

[Spokes]

Just to be rouge...I have never installed a new clip or link on the timing chain. But I always remembered which way the clip faced. That means the clip retainer goes butt 1st in the direction of the rotation.

[Larzfromarz]

Or the closed end in the direction of rotation in case you don't know your "butts".

[Smithers]

Sounds like a freak thing to have the chain come apart like that. I guess we just need to use good judgment when reinstalling used master links. Something to inspect a little closer next time. Just like re-using those piston circlips.