Unstyled Model D locked up

[BenCase930]

Hi All,
We have a 36 or 37 (I think) Model D and it was turning over a few months ago, couldn’t get any spark so had the magneto done up, reinstalled and was able to get it to fire. Then one day I was cranking it, trying to get it to go, left it for the night and came back to it the next day to find it locked up. We pulled it out of the shed today to try and tow it to get it to maybe break free but seems to be fully locked up. When it was turning over we made sure all of the valves were free and moving, what steps should I take in trying to get it free? Also to note, tractor hasn’t run in probably 20+ years.
Cheers, Ben

 

[MSD]

Did you pull the spark plugs to see if it is full of fuel from the needle and seat leaking?

 

[Watthour]

Removing the plugs would be the first step, just as MSD advised.

Presuming that it pulls normally when out of gear, we might guess the problem isn't in the trans. Is there ANY movement out of the flywheel, even a few degrees? How about axial movement of the crank?

I'm guessing you pulled the lower cover before to look at the valves/rockers while you were cranking it. Have you done that again now that it is locked?

 

[Watthour]

BTW - I think you're pretty close on the guess about the age. I suppose the serial plate below/right of the shifter is no longer there, or that would be pretty definite. I had a '38 on all rubber which had a lot of the same visual clues.

 

[wore out]

Hi All,
We have a 36 or 37 (I think) Model D and it was turning over a few months ago, couldn’t get any spark so had the magneto done up, reinstalled and was able to get it to fire. Then one day I was cranking it, trying to get it to go, left it for the night and came back to it the next day to find it locked up. We pulled it out of the shed today to try and tow it to get it to maybe break free but seems to be fully locked up. When it was turning over we made sure all of the valves were free and moving, what steps should I take in trying to get it free? Also to note, tractor hasn’t run in probably 20+ years.
Cheers, Ben

My late Uncle and I used to have an unstyled "D" that didn't get run much and it would "lock up" while sitting from time to time.

The theory was that while operating gasoline would soften up "varnish" on the pistons and if conditions were right after shutdown when residual gasoline evaporated that piston(s) would stick in the bore.

We would thread a light logchain through one of the "keyholes" in the flywheel and use that along with a crowbar to break it loose.

If nothing mechanical has happened to yours and it's not "hydrolocked" something similar may have happened.