Seized engine '50 Panhead

[loch]

I've been bringing my 1950 Panhead back to life after sitting dormant for a long time. During this period I did put a small amount of engine oil in the cylinders and cycled the kicker a few times. The oil and fuel tanks were also drained. Flash forward to a few weeks ago. After new plugs, new points and coil, timing checks, lifter checks, new gas and oil I followed the standard starting procedure and it fired up after the second kick. I put about 30 miles on it after getting the idle adjusted and started to play around with the high speed needle. Then two days ago the exhaust turned dark grey. I only ran it for a few minutes that day. I noticed that it was difficult to keep it idling after reaching operating temperature. Same thing yesterday. But the day ended for me when I heard a distinct metallic squeak and the engine stopped. I said, "Now the didn't sound good." I've never experience a seized engine before this. But something told me my world had just changed. I attempted to turn the engine over. Just to confirm it. Yup, I can stand on the kicker and it doesn't budge. It's now a really cool albeit over-done foot stool. One that I can only use in the garage because, well, my wife would probably scream if she saw me using it in the kitchen to get the high ball glasses down from the back of the cabinet.

So yesterday I put some WD40 in the cylinders. This morning still no movement. I suspect I'm going to have to pull the heads but before I do I would like some advice, pointers, other things to try before doing the drastic. I tend to ignore the simpler solutions but I'm learning. Thanks, Loch

[T. Cotten]

As a diagnostic when you tear down, Loch,...

Please bubble-test your intake manifold before you remove it.

....Cotten

[ryan]

My friend had about the issue once and it was the generator that locked up, I sure hope that is the case with you as well. Good luck!

[loch]

Thanks T., A bubble-test insinuates a manifold leak which would also insinuate a running engine to create the pressure that would cause the bubbles to form. Am I missing something? The bubble-test only works if you create a pressure differential to the inside of the manifold, e.g. the engine is running.

[T. Cotten]

Thanks T., A bubble-test insinuates a manifold leak which would also insinuate a running engine to create the pressure that would cause the bubbles to form. Am I missing something? The bubble-test only works if you create a pressure differential to the inside of the manifold, e.g. the engine is running.

A pressure differential for sure, Loch!

But all the variables of a running motor are eliminated: http://virtualindian.org/11techleaktest.html.
(Please note that a constant, regulated air supply, of no more than fifteen pounds is required, so bubbles will display even the tiniest micro leaks.)

If you get obvious leaks, then they are a likely culprit,... But never does only one thing go wrong at a time.

Let us know how it goes,..

....Cotten
PS: I must note also for a Panhead, their inlet nipples and rivets often show issues, and even the pan cover screws over each intake port are occasionally perforated, so should be tested. Bubbles tell all.

[PaulCDF]

BUMMER!

(Here I am talking mostly to myself): Don't panic. You were not hurt AND you have the bike. Proceed in a systematic step wise fashion. Make notes. Take pictures.

But before you do anything maybe DO get down two of those high ball glasses and enjoy your favorite beverage with your wife.

Please post findings and progress.

[T. Cotten]

..Don't panic... Proceed in a systematic step wise fashion. Make notes. Take pictures.
...

Paul is right, Loch,..

Have you rocked the bike in and out of gear to make certain something in the powertrain hasn't bound?

Then opening the primary and putting a wrench on the motor sprocket is time to panic.

....Cotten

[JoJo357]

Sorry Lewis~but Dark Grey exhaust, followed by a metallic squeal, are never good signs. Hope i'm wrong!

*M.A.D.*

[loch]

I just completed the rock test T.

Rock test

Preliminary, removed spark plugs to reduce compression resistance in the event pistons moved.
Note: I have not before attempted to push this bike when in gear so I'm not sure what to expect.

1. In 1st gear, clutch disengaged - rocked bike - bike moves back and forth.
2. In 1st gear, clutch engaged - rocked bike - bike does not move.

Kicker/tranny test

1. In neutral, clutch disengaged - cycled kicker, no resistance.
2. In neutral, clutch engaged - cycled kicker, frozen near top of stroke.
3. In 1st gear, clutch engaged - cycled kicker, frozen near top of stroke.
4. In 1st gear, clutch disengaged - cycled kicker, bike moved with each stroke.

Unless I'm mistaken - the last test tells me the transmission is probably fine. With the transmission in gear and disengaged from the primary chain, the bike moves forward as a result of the kick pedal going down and turning the transmission gearing.

[T. Cotten]

Come to think of it, Loch,..

The intake valves have to be shut to bubble-test the manifold. Even removing the pushrods means the crank must move.

A feel with a wrench on the sprocket nut might give a glimmer of hope.

Otherwise, disassembly will be a real Gordian knot.

....Cotten
PS: Please do not release the cylinder base nuts while still under valve spring pressure.

[loch]

Good pointers, T.

I'd thought about the valves needing to be closed for the pressure test. Unless I misunderstand, the valves don't travel that far so shortening the pushrod adjustment should allow the valves to close and release some of their tension. I mean the pushrods can be replaced without disassembling the top end. What are your thoughts on this?

I've also read about using Kano Kroil (rated on more than one site as the best penetrating oil). The WD40 didn't work, but this stuff might.

[T. Cotten]

Although I keep cans o' Kroil on the shelf, Loch,...

This isn't a problem that will be solved with an elixir out of a bottle.

The pushrods will not come out without rotating the crank, or bolt-cutters.

(Hence the Gordian Knot reference.)

...Cotten

[loch]

T, keeper of the elixir!

This morning I loosened the front pushrods and was able to remove the intake pushrod. Then for some reason I pushed down on the kicker and to my surprise I felt less resistance than yesterday. Peering over the machine I saw it was in 1st and the clutch was engaged. So I put it in neutral and reengaged the clutch, jumped on the kicker and it moved about half a stroke. The front exhaust pushrod then came out with little effort. I loosened the rear pushrods and was able to remove the rear intake pushrod. Then I put the bike back in 1st, engaged the clutch and proceeded to rock the bike back and forth with a great amount of purpose and gusto! With the bike in neutral again, and while eyeballing the rear exhaust pushrod I was able to cycle the kicker just enough to get the lifter to drop to its lowest point. Pop, out came the pushrod!

Time for that all telling pressure test on the manifold. - But first, a trip to the hardware store to get the regulator.

I did observe a requisite amount of oil around the lifter block bases where the pushrods mate, I also noticed the pushrods had a sheen of oil on them. All normal I think, and perhaps indicative of at least the scavenger side of the system is working.

[T. Cotten]

Great progress, Loch!

Please remember we will be testing the manifold for forensic clues, to see if maybe that's where the fuse was lit; Testing for final re-assembly is far more critical.

(I sold out of all my cheap regulator kits at Davenport, so now I must schedule my annual seventy-five-mile round trip to Harbor Freight.)

....Cotten

[loch]

Thanks and no worries about the kit. I need to wait for the blanking plate to arrive before I can go to the hardware store. I ordered a Linkert test plate from one of the online stores. It has a through fitting that the manifold connects to (that will have to be tested as well). I thought it came yesterday but those were parts for the shovel.

I was thinking I could just run the test with the manifold on air compressor but that would mean having to sit right next to the compressor while doing the test. I've had enough time working around loud equipment while I was in the Nav. So I'll get another manifold and do the test in relative comfort.