Allis chalmers 170 diesel hard starting

How many hours are on it??? Remember, the older a diesel engine gets (hrs of use) the harder it starts, especially when cold and the first start of the day. The following components are all suspect: injectors......injection pump......intake manifold heater (does it have one?)....starter speed.....battery and cables.....and lastly pistons/sleeves/rings/valves/valve seats. Where do you want to start?? I've never seen your tractor, but can tell you what I'd do if it was mine (assuming it runs just fine and has good power). I'd make sure I had the biggest output battery that would fit in the tray (like 1000 CCA) and excellent sized and condition battery cables to the starter and ground. I'd have the starter freshened up by my local rebuilder. I'd make sure the intake manifold heater worked and a good engine block heater also worked. I'd have 10W-30 or 10W oil in it for Winter use. That's what I'd do if it was mine.

Not without looking it up. Timing never changes on it's own, so don't think that's what your problem is.

Oh ya and it has the thermostart set up on it but it's not hooked up. Is the thermostart a good system or should I look into something else

How to you go about testing and repairing the Thermostart system. I thought I read here that usually they are not working on the average tractor.

Interesting about the starter, I should have it refreshed, it is a 1973.

The timing on a Perkins with a CAV pump is simply lining up the mark on the flange.

My opinion on the battery/starter is this:......that engine almost needs TWO batteries to whip it over when it's really cold. Problem is, there isn't room for two batteries under the hood. So, short of making an external tray for a second battery, find the biggest most powerful you can and get it under the hood, use a block heater and light weight motor oil in the Winter months..

DSeries4 wrote: White smoke when cranking is usually a sign of low compression.  Might want to pull the head and take a look at the valves.  At temperatures over 45 degrees in Ontario, my 175 diesel (248 Perkins compared to your 236) fires right up on the first try with no ether and no manifold heater.

Yeah, but 45 degrees in Ontario is HOT!

(Metric joke there.... )

I do have a big NAPA commercial battery but what made a BIG difference on mine was adding a gear reduction starter. Best $225 I ever spent on a tractor. Search for a post about that starter under my name.