Topic: Primary chain rubbing, Replace?

[clarkjh]

74 CB550K
When I split the case I found that the primary chain has been rubbing a bit.  The clock had about 32,000 miles, should I replace the chain or is this just from someone thrashing the #$%* out of the engine?  Is there a test to see if the chain is worn out?

James

[fang]

I am having a hard time understanding the picture.  Can you post us another?

IF the primaries have been rubbing that is bad.  Period.  I would replace them and the tensioner.  I just ordered (what I am hoping is) a chain set from MrCycles.com.  With shipping it cost $95.07 ($79.07+$16.00 shipping);  They are expected to arrive in about two weeks (around 07-31-06)
 
CHAIN, PRIMARY (68L) for 1971 - 1978 Honda CB750K.  23131-300-315 (updated)  $79.07
TENSIONER for 1971 - 1978 Honda CB750K.  13620-300-010  $58.64
information from www.mrcycles.com -- (800)359-0567

Hope that helps
Peace and grease
-fang

[clarkjh]

Here are a couple more pics.  There isn't a tensioner that I can see.  The two rub spots are on the cast oil was to/from the filter and the transverse way across the bottom of the engine.  I don't want to rub through a pressure oil way .

James

[TwoTired]

I don't believe the Cb550 has a tensioner.  If the chain is rubbing the case replace it.  I would scrutinze the sprocket teeth for wear, too.  Not sure what to do about it if wear is found, though.  But, I would sure check out the chain flop with a new chain installed.

Cheers,

[clarkjh]

I'm starting to think I should never have opened this can of worms .  So far, new pistons and rings, new seals, new gaskets, new clutch, now new chain.  Oh well, I'll have a band new engine when I'm done   The BIG plus is that when everthing is done I will have a bike with character not just one riding it.   The wife is starting to get mad that she hasn't had a bike ride this summer.  Looks like she won't till next year the way things are going.

James

[fang]

Duh!   I'm sorry I was not paying attention that you clearly said this was a 550!  I thought I was looking at a 750, and that picture didn't make any sense -- a 750's case and chain are totally different!
 
Good luck!
-fang

[bryanj]

If the chain has touched you definately need a new one, its worse on the 500 than the 550, obviously fit a new cam chain at the same time and there are 8 rubber cushions inside the unit driven by the primary chain which are worth replacing and dont cost much. Cheapest place i found is www.davidsilverspares.co.uk

[clarkjh]

The local stealer has both the chain and rubbers for about $150 CAD.  Have to save up a few more pennies .  I already have a new cam chain.  While I'm putting all these new parts in I'm starting to think I should have the head leveled while it's apart.

It's only money , and to me the bike will be priceless.

James