Motorcycle Repair: CBX1000 1979 rod problem, piston pin, precise circumstances

Question
Hi Jan,

I have a CBX1000 with a problem related to the piston #1 that hit the crankshaft. I did a search on internet and I found you wrote some comments related to a similar problem. what got my attention is that you wrote: "Usually it's #1".
I know it may look like a silly question, but may I ask you why ?
may i also ask you how to measure if the problem is always on rod or may be also the piston pin?
i add one more detail: i had the noise only after warming up the engine. when cold, I had no noise. is it also compatible with your experience?

Regards
Paolo (Italy)

Answer
Usually it is #1 because people leave the fuel on, and the #1 carb is the first to fill up when the bike is on the side stand.  The hydrolock happens when the engine is turned over when #1 is full of fuel.  The extent of the hydrolock depends on the precise circumstances, but the piston hitting the crank is a mild case.  You will have to replace the connecting rod to fix the issue though.

Good luck,  Jan