Topic: stretched cam chain?

[CBDee]

74 cb550. Can anyone tell me what the symptoms would be for a stretched cam chain? I tried to adjust chain but no joy. Adjusted as far as it will go. Bike runs rough,backfires, and, after revving engine there is a loud rattling noise. At my wits end trying to get it to run. Any help appreciated.

[Deltarider]

Adjusted as far as it will go.

What do you mean by that? You're not supposed to turn the bolt, only the nut. Then, what is it like at a true 1150-1200 rpm? Have you done the 3000 mile service?

[CBDee]

Have done tune-up, ignition timing correct, synched carbs (all readings even, but could not reach 15cm , so all readings low). What I meant was that there was no movement of adjustment screw when nut was loosened. Tried moving it with screwdriver to make sure it wasn't stuck. It was free but no improvement. This is an engine I got off ebay. Runs like crap and is noisey, rattles on the de-rev.

[HondaMan]

Rattling in the 550 can also be the primary chain...especially during decel.

[bryanj]

If a po has been at that screwdriver slot and turned it hard it can wreck the gear and rack arangement that locks the tensioner, only way to find out properly is take it out and check.

[CBDee]

Rattling in the 550 can also be the primary chain...especially during decel.

Thanks for the reply. I'm not running the bike, so primary shouldn't apply, should it?  Just revving the engine produces the rattle. Could this be cam chain?

If a po has been at that screwdriver slot and turned it hard it can wreck the gear and rack arangement that locks the tensioner, only way to find out properly is take it out and check.

Been mechaniching for many years so know better than to hard crank anything. I just tested the stud to make sure it turned. Stud was free.

Thanks for the replies. Don't want to tear into engine unless I have to.

I'd be happy to answer any questions. Just want to get this running!

[Korven]

Rattling in the 550 can also be the primary chain...especially during decel.

Thanks for the reply. I'm not running the bike, so primary shouldn't apply, should it?  Just revving the engine produces the rattle. Could this be cam chain?

If a po has been at that screwdriver slot and turned it hard it can wreck the gear and rack arangement that locks the tensioner, only way to find out properly is take it out and check.

Been mechaniching for many years so know better than to hard crank anything. I just tested the stud to make sure it turned. Stud was free.

Thanks for the replies. Don't want to tear into engine unless I have to.

I'd be happy to answer any questions. Just want to get this running!

The primary chain is moving when the pistons are.

[CBDee]

Good point that I realized was true while thinking abt it. Thanks for the replies.

[bryanj]

I did say "IF PO HAD CRANKED THE STUD"  Its not what you have done but before that causes the problem. If the cam chain is rattling chances are it will need changing so openining it up may be the only way.