'47 CJ-2A Problem

[1947Willys]

Hello Everyone!

I have been restoring my grandfather's 1947 CJ-2A, but I've run into a problem. The starter turns the engine over when the spark plugs are out, though slower than it should. When I put the plugs in, the added resistance prevents the starter from moving the engine. I hit the switch and the fan moves a couple of inches at best. When I ran into this, I sent the starter to Kaiser Willys to be overhauled. The problem persisted, so I sent it back. When they tested it, it was perfectly fine. I've tried using jumpers to go straight from the battery to the starter, but it made no difference.

The engine and transmission have both been overhauled (the power take off was removed when the transmission was overhauled).
The battery is new and charged.
I've replaced all the cables and made sure everything is well grounded.
The engine has oil and the cylinders are lubricated.
The transmission and transfer case are both in neutral.

Does anyone know what might be causing this? Could I have done something thing wrong when installing the transmission that would cause this friction, but would not stop the engine entirely?

I've run the starter for a about a minute straight to see if it just needed to move some before putting the plugs in, but there was no improvement. I'm worried about trying again if whatever is causing this will damage the engine.

[LarrBeard]

Troubleshooting by remote description is hard to do, but here are some thoughts.

I'm assuming you have the L-134 flathead. The good thing about the flathead is that there's nothing to get in the way of a piston as it comes up - unless someone left a shop rag in the top of the cylinder (very unlikely...). Not much risk of breaking anything by cranking it.

A. Turns over slower than it should with plugs removed. A newly overhauled tight engine will turn over slower - I can't judge just how much slower it is, but that may or may not be a hint of what's going on.

B. Won't crank with plugs in. Sounds like there is a timing problem where you are trying to compress a cylinder full of air against a closed set of valves. The good news if this is the case is that you probably have good valve seating and solid compression. The bad news, you'll have to take some things apart to see what's happening. With the L-134 it's easy to pull the head and check how valves are opening as you come up to TDC.

You might try just putting one plug in. Crank it - and if it stalls against one plug, I'd suspect the valves aren't timed properly.

Or - as we have all found at one time or another with old Jeeps - it could be something totally different.

Let us know what you find. Someone else is having the same problem, they just are afraid to ask and we need to know.

And, oh by the way - if the dipstick gets up against a counter weight on the crank - it makes a real racket but doesn't hurt anything right away.....Gets your attention though!

Just discovered that today.....