Topic: 79 CB750F bits found in oil pan.

[thrutheframe]

I'm refurbishing a 79 CB750F.  It needed a new oil pan gasket.  When I pulled the pan I found lots of RTV boogers, what appears to be Hondabond boogers and a few other choice pieces of mystery.  Below you'll see pics.  The bits from left to right are:
 
Two plastic bits that look like the remnants of a plastic sleeve.

One ferrous chunk of unknown origin.

Five pieces of aluminum with threads that appear to have been a thread well at one time.

And

One aluminum washer 10mm ID x 20mm OD.

The motor overall has RTV at every gasket, I've had it running, compression was good, no odd noises.  I've had the valve cover off, the thread wells for the cover are intact.  Could someone have been try to sabotage a PO?  Catastrophic failure followed by a ham-fisted attempt to repair it?

Any ideas?

Thanks.

[calj737]

Geez, I'd have to scour four bins of parts to pull that much stuff together, let alone finding it in the oil pan!

My suspicions would be: RTV is perhaps from the oil pan/filter housing? Washer, God only knows. Damaged and destroyed heli-coil maybe from the oil filter bolt into the case lower on front? Or, a lower case tapped hole that should have a bolt in it, doesn't and that failed heli-coil is the reason why.

The oil filter heli wouldn't explain how it got into the pan, but proximity during negligent prior ownership might...

Plastic bits maybe cam tension? Ferrous chunk, associated with the failed heli-coil?

I think you might want to get on your back with a flashlight and take a VERY good look underneath. Refer to manual pictures for verification that everything is in tact.

[thrutheframe]

Caj I'm curious about where your heli-coil comment comes from.  The threaded bits are definitely aluminum.  Can you elaborate?  I'm just trying to piece together the mystery here.

[ekpent]

Do you know if the engine was ever worked on or torn down before you. Who knows what can get dropped in while apart or working on it like that washer. Is that washer big enough to be a cylinder stud,nut deal for the head ? Looks kind of thick like an SOHC.

[calj737]

I thought heli-coil as you indicated "thread well". Might have been an insert into an underside bolt hole that failed. It's all speculation until you verify the condition of the internals best you can.

[thrutheframe]

Ekpent this engine has RTV poking out the sides everywhere you look. As far as it being a cylinder stud washer 10mm ID is probably too big.

It's certainly a mystery.

[thrutheframe]

Ek....  Hmmm you might be onto something.  Found that on eBay by searching "cb750f aluminum washer". They're calling it a "cylinder head sealing washer".

[Don R]

 I wonder if a too long bolt bottomed out in a shallower threaded hole. Might have broken through and not even stripped out.

[thrutheframe]

I wonder if a too long bolt bottomed out in a shallower threaded hole. Might have broken through and not even stripped out.

Or not enough thread on a shoulder?  I'll have it buttoned up enough to start again this weekend.  I'll definitely be listening with the stethoscope.