Don't Let This Happen To You

[The JET]

  I don't post a lot on here because I don't like to type, but I thought I would this time just to point out what can happen to our beloved Valk engine.  Don't worry this is not my bike.  It is just an engine I am using for parts.  It did hydro lock and bend the rod. This appears to have happened before as there are two signs of where the piston has stopped at TDC.  The second time the rod bent severely and the piston hit the crank and broke the rod and busted the case.  This bike took a Motor and the Petcock Repair and all is well.  This engine did not break the starter gears or the housing, just bent the rod and snapped.  
 On all of the petcocks I have repaired, the common problem is the Diaphragm is cracking  in the center area from excessive movement back and forth.  Honda made a poor decision when they only put one intake tube on the diaphragm, and it pulsates instead of just opening up and staying open.  Mine failed after a couple of years.  I then teed all the Vacuum line together to make a constant signal to the Petcock Diaphragm.  This diaphragm has lasted 8 years and no further problems.  
 So don't learn this the hard way, check your petcock and Tee more Vacuum lines to it for a better and more constant signal.  If it acts like the battery is dead,  don't jump it till you check for fuel in the cylinders.  If you  suspect  Fuel, just put it in 4th gear and push it backwards for about 10 feet.  That will expel all the fuel out of the cylinders.  Hydro-Lock was a very common problem on our Injected Sprint Cars and we "Backed Them Thru" every time we pushed started them.  

Don't Eat Too Much Turkey & Be Careful Out There!

The Jet

[Gear Jammer]

interesting suggestion on the T vacuum lines

[Disco]

Thanks for the post, the JET.  Great pointer on how to "Back Them Thru". 

So, whatcha doin' on 5 December???  Do you have a parts list / schematic for your Teed Vacuum lines?

[Rocketman]

The "T" sounds like a great idea.  I don't have the stock petcock anymore, or I would do that. 
As for "backing it through", I'm a big advocate of that for at least verifying hydrolock.  If I ever think there's a possibility on mine, I put 'er in fifth gear, and walk it forward a little (I don't know that forward or backwards matters at all).  It's easy to feel the difference between the compression of air vs. liquid.  If I feel too much resistance, I pull the spark plugs and then roll it again.  That will clear the cylinder with less stress on the engine parts.  Some advocate pushing the starter button, but the less electricity you have flowing while gas is shooting out, the better in my opinion.

That's the first time I've heard of a hydrolock breaking a rod.  I'm surprised that the rod went before anything else.