Oliver 770 Carburetor adjustment

I'm new to this forum, engines, Olivers and tractors. I've had the tractor for a couple of months or so and when its running at full load the choke had to be out a little more than halfway or just using any hydraulics would stall it and it had to start, every time (warm or not), completely choked. But the last few days it'll start just like before but if any pressure is applied to the engine, ie moving forward or backwards or any kind of usage of the loader or grapple it sputters and I have to apply the clutch to get the rpms back to make another run at whatever needs to be done. A little history: I bought this beast in November which was cold, but nothing like what it was in December and is happening in January reaching highs on a lot of days around 0? farenheit. In the last month the points went bad, both of the tilt arms seals blew out, the starter went out, I ran it out of gas...twice, and now a seal in the lift arm is leaking pretty good. The reason that I think the carb is all wrong is that I have to mess with the choke an awful lot to get peak performance, but since its gotten cold I've had nothing but issues, picking up hay and moving it fifty feet takes more than a half hour due to stopping and restarting movement, the engine doesn't die, but the rpms drop significantly. Power is way down compared to what it was when I got it, and it felt like it was unnaturally low even then. Carburetors freak me out, they're so sensitive and I need this tractor to work so I haven't touched it (the carburetor). Oh and the guy I bought it from said that he "just" rebuilt the carburetor, but I don't know if that was 9 years ago and he just didn't use it very often or if it was last summer. I really don't want to rebuild a carburetor at all, but especially in the arctic air. My garage is unheated and has a dirt floor and my wife would have some serious problems with doing anything with gas all over it on the dining room table. I know the basics about engines, rpms, etc, but after reading some of the posts in this forum I understand that most of you are far more advanced thinkers than I am, so feel free to explain things in great detail and appropriate verbiage, if I don't know what you're talking about I'll look it up or I'm not afraid to ask questions, and pictures sure don't hurt.

Thank you so much
Russel

My first thought was whether the carburettor is icing up. Some olivers can suffer from this but I don't know if your model is one of them.

Is the engine actually getting hot? A faulty thermostat can mean it is being kept far too cold for proper running.

Are there leaks around the inlet manifold? What colour are the plugs running if it can be run for a while without changing things?

If it is carburettor settings, it could be float chamber level, poor supply into the carb, main jet blockage and possibly a lot more. One thing is for certain, it should run better than you are describing!

RAB

Do you have good clean fuel and points set right? Have you drained the carb. I think alot of carb problems are ignition problems.

Points are accurate, fuel is clean. Drain the carb?

I put some Heet in the tank on the last fill-up, I don't know if its getting hot, I'll change the thermostat, and I don't know what the inlet manifold is.

And I don't know what color the plugs are...what color is bad?

It sounds to me that its running lean if you need to have the choke out to make it run, if the carb is a cast iron Marvel Schebler there is a main jet at the bottom of the float bowl it could be a T or L shaped turn it out counter-clock wise a quarter of a turn with the engine running and see if it improves if you go to much the exhaust will be black.
GB in MN

I always drain the carb to eliminate water in the bowl or old gas. You're probably OK if you have good gas and best in it.

I sent you an e-mail, did you receive it? J.