Topic: Binding connecting rod?

[KingCustomCycles.com]

I am well into tearing down and repairing my 69 KO motor and found one binding, stuck connecting rod.  I assumed it was corrosion but upon disassembly, there is nothing visually wrong with the rod or cap.  I cleaned it up thoroughly and it still binds.  This only leaves distortion, or out of round.  Has anyone heard of this before?  Thank you.

[754]

I have seen corrosion in one sopt on the bearing, looks like a little fisheye on the bearing, maybe from acids in the oil. Examine very closely, wont hurt to replace.
 I would get machinist dye or paint and blue the side of the rod and assemble, see if it shows a problem on the side clearance.
 I could be something else like something under the shell bearing.
 Deal with it, or it will eat the crank.

[KingCustomCycles.com]

Shell bearing?  These appear to not have bearing inserts.

[scondon]

On the small end, the end the wrist pin goes through and mounts piston, there is no insert. On the big end that connects to the crank there are two "half shell" bearings. When the cap is removed you can easily remove the two bearings. It may appear to be one piece(crank/shell bearing) but you can see a tang resting in a cutout in the crank/cap at the end of each shell bearing.

   There are some differences in the early '69 models that I am unaware of, but I don't think absence of bearings in the crank is one of them. Others will know for sure.

[754]

So are you not looking at a manual, before opening this up?

[wrenchmuch]

Try assembling the rod without the bearing shells and using a telescoping bore gauge to check for oval . Set the gauge at one position inside the big end and rotate it to see if it gets tighter or looser . How does the bearing and the crank journal look ?

[scottly]

The rod caps and the rods are machined as an assembled unit. They need to be re-assembled in the original orientation. I suspect a PO improperly assembled that rod.   

[phil71]

Was this engine stuck before you dove in?
'binding' usually means a bent rod. check your centers with some straight edges as best you can.

[KingCustomCycles.com]

Rods and caps are always machined as a set with a single orientation.  Honda used ink etched numbers to orient these.  One on the cap and one on the rod, across from each other.  I will pick up the telescoping gage set today from work.  The journal looks very clean but it will be checked for out of round also.  Thanks guys, I'll post results. 

[KingCustomCycles.com]

Mystery solved.  I didn't think I was seeing rod bearings in the rod.  They were stuck to the crankshaft and had been polished from running to the point that nothing looked wrong from the outside.  The bearings were welded nicely to the crank.  The PO told me the engine had sat and then got stuck.  Truth is, it got stuck then sat.  Can I blame him for this little mix-up?

[wrenchmuch]

Ouch!! Sorry to hear that . You can try and blame him and the other PO,s that came before him ( never seems to work out for me when I try it ) . Bad maintenance . Wonder if something blocked the oil passage in the crank from the main journal to the rod journal . How did the main bearing that feeds that rod look ?

[KingCustomCycles.com]

It was scored and heavily worn.  I am removing and replacing the entire crank, rods, and bearings from another engine.  I'll check them for fit and funcyion and press on.

[754]

check the numbers/letters on the crank and crankcase, if you swap cranks...to make sure bearings are correct.
 I would hang on to the crank or fix it, if its only one journal thats bad.