Chain Life? (not drive chain)

[Captain Farmboy]

Not sure how to ask without sounding ignorant, so here goes. My bike has 49,000 miles on it.

I just finished a year of engine cleaning, new piston rings, beautiful exhaust header-pipes from eBay. Now that it's running, I feel so dumb.

Should I have replaced the chain driving the camshaft, just on general age? Also the counterbalancer is chain-driven and the spring tensioner is at the end of its reach.

I know the engine will grenade if either fails. What's the probability? I can still get new, for a price. If I can get a gently used one, say, 8500 miles, should I get the used one?

How long will these things last? And will the cam chain stretch like the balancer chain probably has? Anybody got any experiences with these?

Thanks in advance.

[Kenneth_Moore]

Cam chain life is a function of adjustment. If your bike has an automatic tensioner, the chain will last almost indefinitely. If it's manually adjusted, and it's been neglected, it's a roll of the dice.

I wouldn't buy a new engine over it.

[pplassm]

With that many miles, I'd have included a cam chain replacement in the overhaul.

The chains stretch over time, and, even with proper tension, the increased pin-to-pin distance on the chain can alter the cam timing to less than optimal.