I'm really not familiar with the innards on these motors, so i'm just kinda fishing to see if anyone has any ideas before we go tearing it apart. The engine will only turn 360* (roughly) in either direction. Its acting like it has a timing stop installed. I can grab the fan and turn it one way and it hits a dead stop, turn it the other way and it does the same thing at the same point. Can't really tell where it might be hanging up, so ai'm wondering if any of you banger guys might have some insight that I wouldn't. Is there anything internally that is prone to failure that might cause something like this? Thanks in advance.
Its an older build with a winfield head. It came to me for electrical and when we went to start it it went clunk.
If something got into one of the cylinders as that would give you almost 360. I had an in-line six that had sit for a long time drop a Chunk of carbon from the combustion chamber do the same thing. More info about the history would help. Sent from my iPad using The H.A.M.B. mobile app
Depending on the Winfield head there isn't much clearance between the head and the piston at TDC Have you pulled the plugs and looked to see which piston is TDC when it stops?
Also, pull all of the plugs, and try it again. I have seen over-long plugs do this, on certain motorcycles.
I had this experience once before, working on a model A roadster with a fairly fresh engine. What had happened was the fellow went to start it with the lever fully advanced,and the bendix bolts sheared. He replaced the bendix and did not make that mistake again. Time went by, he was driving along and the engine locked up. Same thing, turned a bit both ways but not full rotation. One of the sheared bolt heads from the bendix got caught in the crotch of the flywheel housing where the engine mounts are, it stayed there until it rattled out just enough to lodge into the ring gear and stop the engine. The other sheared bolt head was in the bottom of the clutch housing. Had to pull the engine to figure it out. We thought it had a broken crank or worse. Crazy stuff. Just a thought.. Good luck buddy..
I doubt this is your problem but I bought a B motor that did this an when I tore it down there was a mouse crushed in the cam gear. Still not sure how he got there.
I had an outboard that a tiny chunk on the edge of the piston above the ring land broke off and it did the same thing
help me out here... what lever are we talking about? BTW the plugs and starter were the first things we pulled out. no help.
You can figure which pistons are up by finding the timing mark with the timing pin in the front cover. These engines have two pistons up and two down at the same time, when the pin drops in the #1 and #4 pistons are up, #2 and #4 are down. Don't know what you can do from there to find the problem without pulling the head.
the lever in question is the spark advance lever, on the left side of the steering column. on the right side is a manual throttle. the spark advance lever must be up, retarded to start the motor. if not, you will note the strain on the starter motor you know from a motor being too far advanced while trying to start it, and in the case of a model A ford it can bend the armature shaft in the starter. so, start with lever up, once running pull the lever down 1/3 to 1/2, drive it, then if out on the open road full advance, down. didnt solve your problem, but hopefully prevented the next one
I have seen instances where a tiny bit of rust on a cylinder wall can really stop up the works. A good squirt of you favorite penetrating oil, in each cylinder, left at the point where it locks up, and left overnight, should fix that, if that is what it is. Cheap, and easy to try.
I called the owner and he "forgot to mention"... He had the plugs out while working on the carburetors or some such thing and short story, "something might have fallen down in there" Pulled the head off and indeed it was some round thing that is now a flat thing. That's what it felt like. I even called it on the #3 cylinder.
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