Topic: All tore down

[eigenvector]

Sorry if I'm spamming this place with progress reports, I promise this should be the last one. 

I got my CB550 wrecked engine all tore down and I'm amazed at how clean it was.  The exterior looks pretty bad, but inside, fine.

Only two things immediate jumped out at me as being a problem.  But mostly it looked perfectly fine.
1)  Adjust the cam chain tensioner?  Why would I do that? 
  Whoever owned this thing before me obviously never adjusted the camchain.  It was set to its minimum adjustment - basically the position you put it in when you want to insert it and then install the cam chain.  It was worn, right where the chain rubbed against the metal because the runner wasn't contacting anything.  But just as annoying - because the chain was so loose it wore the return guide out.  The BACKSIDE of the return guide - yes really

2)  This actually ties in with a previous post of mine, on how to ride in heavy traffic with an air-cooled bike.
  That engine was baked.  All 4 pistons had a thick crust of sludge on them that had burned into a solid mass.  I rapped it with a screwdriver tip and it flaked off to reveal the shiny pistons beneath.  Same with the valve - all cooked like gooses.  The head gasket flaked off like a pie crust - never seen one come off that easy before.

3)  No indication of running problems with the spark plugs.
  Yup, the original factory spark plugs were in this thing and they looked about like you would expect on a normally running engine.  Some oil, some carbon, but mostly white/tan.  Very worn out.

4)  One bent exhaust valve. 
  I am assuming this occurred when the chain broke because the cylinder itself didn't appear to be messed up or otherwise been run on a bent valve.

Incidentally, I was astounded by just how easy it was to straighten out that bent valve.  2 very light taps with a plastic tipped hammer and it went right back to where it should have gone.  And that valve was sticking out pretty far.  The kink must have been pretty far up the stem.  I never would have thought that a couple of <tink> <tink> and all fixed it would be.  Now that said, I don't expect it's perfect, the guide might be messed up - but then again it might not be.

I bet this engine has less than 5,000 miles on it.  My guess based on what I'm seeing - a new rider who didn't understand the concept or couldn't do the periodic maintenance, and cooked the engine in traffic jamming it, breaking the camchain.  Nice find really.

[eigenvector]

Broke down my second engine tonight.

Had to drill out all the screws - well except for the 2 that had copper washers under them.  Had to drill out the side covers for the valve cover.  The engine case is pristine - no oil, no dirt, no sign it was ever used.

Managed to get the valve cover off, what a rust bucket.  Every part that is steel has rust barnacles on it - valves, springs, camshaft, chain, heck even the sheet metal body of the cam chain tensioner.

Good news, it appears that the internals are in working order.  The cam chain guide looks serviceable, as does the tensioner.

I think I got a really good deal on these engines.  I can clean them both up, replace any of the worn parts, and heck maybe pick up a CB550 with a dead engine - swap it out.