Help Starting D21

Hi all,
I have an Allis Chalmers D21 that’s been sitting for many years now. My Dad use to use it and I’m taking over stuff since he passed. I don’t know much about tractors and am looking for some
Guidance and help.

I tried connecting a battery to get it to turn over before adding diesel to the tank but it won’t turn over. I used a fully charged 650CCA battery and tried adding my jump pack as well.

The starter clicks and sounds like it engages but the motor doesn’t turn over. I have videos but I guess they’re too big for the site to upload(10 seconds).

Maybe it’s not enough juice?


Any advice or direction would be appreciated.

Edited by Newtotractors - 18 Jul 2023 at 12:18pm

it may not want to turn due to the injection pump being stuck. If it's removed and properly serviced before it get's forced to run, it can be saved. If it by miracle does actually start, and fuel is nasty and old gummy syrup, it can seize the head in the pump and that costs much more to fix. I hate seeing people seize these heads up. Yes I can fix the pump, but the head is an expensive piece, and for D21's it's no longer available, and I'm using up my supply of used ones. 

Condition of the fuel is a big factor before proceeding. Was bio diesel used or regular diesel fuel? Hopefully you know what your dad used. If it was bio I wouldn’t even attempt to start it if it has been setting for any length of time. Drain and clean the tank and all fuel lines. Remove the injector pump and have it serviced. Poor Fuel quality can really damage the pump over time. I’m with Ed, pull the pump and have it serviced. It’s best to be on the safe side than cause damage that could have been avoided.
And then check the engine to see if it is free or if it’s a starter issue.   Why was the tractor parked? Was your dad experiencing a issue or just stop using it? Maybe it was overheating or just not running quite right? A blown head gasket with coolant in the cylinders could have it locked up? A lot of things to check before firing it up. Take your time and check things out before you hit the starter button again. It will safe you a lot of misery and cash possibly. Just my 2 cents

If you plan on using it do yourself a favor and pull the pump and injectors and get them rebuilt you will never be sorry. Before the days of biodiesel and fuel still ha plenty of sulfer, a machine could set for years and all you had to do was make sure it was primed and it would crank and fire right up was nothing to worry about. Sadly that's not the case in these modern times.

Edited by SteveM C/IL - 18 Jul 2023 at 6:36am

if I couldn't turn it with the fan blade by pushing the belt tight I don't think I'd be trying to roll it with the starter.....beware!

Make sure the transmission is in NEUTRAL. Stand on the left side of the engine. Grab a fan blade at the top and pull on it while (with your hand) pushing both fan belts tighter underneath the alternator, while pulling on the fan blade. The engine should TURN. If you cannot make it turn, it may be STUCK.

I’m curious, what type of crops did your dad harvest?

Cool, thanks for clarifying that. Just couldn’t figure out what crop would survive there. But then again I am not familiar with the climate there.

Hunted in Alaska with my Dad when I was 18 and we became good friends with my guide. He got a grant to farm around Delta Jct. and cleared land, bought new IH tractors, combine and implements. He grew record yields of wheat and his neighbors grew potatoes. Trouble was it cost so much trucking to get crops to storage or processers. He only did that for a few years till he switched to hay because there were horses in the area that owners used for trail rides in summer and hunting in the fall so there was a market for hay. When he retired he shipped his low houred equiptment to the lower 48 to sell. Remember my Dad saying when he was there one Fall about the mountain of stinking potatoes on the farm next door that there was no market for. Sorry for reminissing hope it was entertaining, Thanks...Harvey

Interesting. Thanks for sharing