Topic: Should I change my 400/4 Primary Chain?

[neilma]

Was just wondering what the consensus was one whether it was necessary to change the primary chain? Just about to start a complete engine rebuild and wondered if it was necessary to change the primary chain? I was reading a review from the 80's that said they were bulletproof and likely to outlast the engine and the owner however elsewhere people say to change them as a matter of course?

Engine has done aroun 34K miles and I have never heard the engine running so couldnt say if it was making a noise before stripdown. If ithelps, the guide shows no sign of wear but not sure how relevant that is. Are there any measurements around to compare to a new chain?

Or should I just change it and forget about it??

Thanks
Neil

[mystic_1]

Changing it now is (relatively) cheap insurance.  I'm replacing the primary chains and tensioner in my 750 for exactly this reason.

mystic_1

[Deltarider]

These are heavy duty chains and they'll live forever. Mine (in a CB 500) is in there for more than 130.000 kms now.

[bistromath]

Deltarider, you might want to rethink that statement -- the CB500 has no primary tensioner and tends to let the primary chain wear through the oil galleys when it gets slack. I *believe* the 400 has a primary tensioner and as such its primary would last longer.

I'd change it just because I wouldn't want to tear it down again later, but if there's very little slack then don't worry about it.

[Tnutz]

Checking mine this weekend by dropping the pan.  Honda sure dropped the ball on the 500 and 550 with that....

[schwebel]

Do it, mine has the infamous CB400f primary howl. The engine has about 20k on it. It drives me nuts sometimes, but I am trying to hold off a little longer on my rebuild.

[Tnutz]

checked mine, there is slack. but not alot.  Cases all feel smooth and no debris in the oil pan.     but if i end up tearing into this motor again soon i'll do it anyways.