Topic: Had a bad weekend!

[75750SS]

After having two heli coils put in my 750 heads, I put everything back on. After setting the timing and syncing the carbs, I went for quick ride around the block.  It was like a new bike. It ran smooth and strong.  Kept riding around town for 20 minutes and everything is still going good. Jumped on the freeway and hammered the throttle.  Everything is still running great (very big grin on face at this point).  Settled down a 70mph cruise and after 5 minutes the engine began to hestiate followed by an awful engine burning smell. By the time I got to an exit the engine seized as soon as I pulled in the clutch.  The cylinder head cover was very hot. If you touched it with a wet finger, it burned you.
Pulled the plugs out this evening and sprayed LiquidWrench in the cylinders. After a few pushes on the kickstarter, the engine is turning over again.

What happened?  The oil light didn't come on so there must have been some pressure.  I did notice when it started that the oil the level didn't change in the tank.  If I remember correctly it should draw the level down when the engine is started and fill it back up when turned off.  Is this correct?

Any technical thoughts appreciated on what may have caused it to seize.

[sparty]

Ooooh, geez that isn't very good.  Sorry to hear about that.

First, I wouldn't trust a 30 year old "idiot" light.

Second, obviously your oil was not where it was supposed to be.  You may have a bad oil pump, or one that isn't working at capacity at the upper limits of the engine.

Third, at least a top end tear down is in order to see how badly the scoring is.

Fourth, it isn't your fault...

Good luck and keep me posted,
Sparty

[tbone]

Wow! That just sucks! Does your idiot light come on when you turn on the ignition before starting?
If so the problem may be a cylinder head-camshaft lubrication problem. A friend of mine just had a
camshaft seize up in just about the same fashion as yours locked up. 

[bwaller]

Could it be that one or both of the top end oil restrictors are blocked? It would have seized the cam first.

[ChevelleSSLS6]

I'm no motorcycle guru, but did did it possibly overheat to the point of seizing?   I wish you luck in getting it back on the road.

[75750SS]

Pulled the engine this morning and removed the heads.  This is what I found. Cylinders 1, 2 were wet with oil. Number 3 had little and cyclinder #4 was dry.  So I'm sure the oil pump is working, it was just a blockage some where in the head.  Lots of black aluminum goo trapped in the head pockets.
Anybody have any good tricks for flushing the crankcase out?

[sparty]

Ummm...  You are not going to like the answer to that question.

The answer is: rebuild

All of those shavings are a sign of damage.  Sorry.

Sparty

[tbone]

If it were mine I'd break her down and start over. Clean everything and replace anything even remotely questionable. Minimally I'd be looking for a new head, cam, rocker assemblies, etc.

Hope it all turns out well for you.

[Hockers Choppers]

That sucks man! I would think the Oil filter would have caught most anything that fell to the bottom  end? There was no oil washing it down. The oil restrictor must be blocked or something is blocking the passage to that side. Take off the oil pan and see whats laying in there. Might be able to get away with a cam and towers?