Why does my choke have to on for tractor to run?

[Geo-TH,In]

Very high probability you have a carb issue.
However my Jubilee wouldn't run without a full choke and it needed points. Go figure. I can't explain that.
A 40 HP mercury mariner outboard would occasionally need a little choke to make it run right and itt couldn't run faster than half throttle.
OLD BAD GAS. Both are rare issues, Carb is most likely.

 

[Mcrafty1]

I agree with Geo-TH,In, likely a good through carb cleaning and throttle shaft/choke shaft inspection will have that thing running like a top.

 

[showcrop]

I agree with Geo-TH,In, likely a good through carb cleaning and throttle shaft/choke shaft inspection will have that thing running like a top.

There are maybe 25 posts about carburetor cleaning before you,

 

[adediesel]

my little story,,,,maybe 30 years ago, we had a jd3300 gas combine. one morning, it did not want to run to run good, short on power to shell corn unless choke was most way out. ok, I could go on shelling. about two hours later it really bogged down and i pushed choke in and it run great, so I assumed a piece of dirt got in a jet and finally moved out. one time we won an issue.