1650 gas issue again

Almost a year ago I was fighting an issue with a poor running 1650 gas. Then it would spit, sputter, and die. Leave it off for 10 minutes and it ran normal. Well I started diagnosing things and the issue pointed toward a carburetor problem. In this time it was due for a tune up. Plugs, wires. It has electronic ignition. Also took the gas tank off and had it cleaned at a radiator shop. Still ran poorly so we ended putting on a remanufactured carburetor. With some minor adjusting the tractor ran great and we used it as the rake and tedder tractor all haying season. I should now mention our land has some rolling hills but not necessarily steep grades. Today we brought the haying equipment back from my brothers property to the farm. There are several long fairly steep grades. Tractor ran fine till part way up first hill. Started spitting and sputtering again. My brother had to downshift to 3rd gear to make it up the hill. Second hill it did the same, stalled out a few times and he was all the way down in 1st gear to make it up. Tractor should pull that hill in 6th direct. The only thing I can think of is maybe the float height is way off causing fuel starvation ? Only happens going up long grades. Gas tank was 3/4 full. Any thoughts ?

Float height was what I was thinking. My old Yamaha Moto 4 would die out like that if I got on rough ground. I adjusted the float and that fixed it.

My thoughts:

Are you 100% positive you have a clean fuel supply? Because my first thought is you've been putting contaminated fuel in it all season. Then the contamination fills the sump when on hills causing it to starve. Maybe that was causing your previous issue as well.


Venting. Does it behave the same with the cap off?

I can see that someone could think that being an issue.
Like I said the tank was professionally cleaned. We use 5
gallon plastic gas cans for the gas. Tractor on flat ground
has good supply if the bolt on the carb bowl is removed.
I would think any sediment of junk in the tank would
settle to the bottom no matter what position the tractor is
in. Just my counter thoughts. Just strange it only
happens on steeper inclines. Runs fine on the rolling hills
at the farm and my brothers property is fairly flat. On any
type of steeper grade runs horrible . Im not saying what
youre saying is wrong, I would probably say the same
thing . Just whats going on doesnt point to that. Thank
you ! Ill post what I find.

Thats the only thing I can come up with now. Thinking a little about this the needle and seat on this carb is toward the rear of the tractor. The front of the float is toward the front of the tractor. If the float wasnt adjusted right and not letting enough fuel into the bowl it would be fine on level ground and going down hill. When going uphill the float maybe pushing the needle close thus not letting enough gas into the bowl. Liquid will always find level even if tipped to 45 degrees. Maybe just maybe when the tractor is on a steeper incline fuel is being restricted by the needle but not so much it is completely shut off. Like I said after a while tractor will start and run again for a brief period. Will have to do some more investigating. Thank you !

going up a hill could shift fuel back in the carb and make the float go lower in the carb and open the needle valve more not less I would think. My take is that it is not related to the hills so much as how much you are working the tractor. The harder it is working the more fuel it needs, so somewhere it is not getting the fuel it needs. could be fuel lines, float valve, main needle valve. Does choking while it is missing make any improvement??

quite easy to find out... when its acting up remove the fuel at the carb and see if it has full flow there. if not blow back with air to tank, as there is possibly junk in the stand pipe in the tank from more tank junk. thats why its handy to have a portable air tank. plus u could unscrew the complete sediment assembly from tank cause it would have junk in it. i hardly think its float level it ran good before. and also pulling the choke out when it acts up is another diagnose for it, if it helps then you know its a fuel problem. also feel the coil if its hot and that can be your problem replace it. and just because the tank was cleaned dont mean it will last forever. rust is rust. and sitting low with fuel you will have condensation to make more rust. plus remove the carb drain and catch the gas into a clean container and see whats in it and if it has good flow there also. its one of these problems. went through the same thing on my 1550.

wonder if it is choking