Depends on your location..
If you live in the snow belt states and its like new..
Probly 4-500..
Gravely snow cannon motto..
"Put it in your neighbors roof"!!
Depends on if you keep the oil changed and if you remove the sheet metal tins anually and blow the dust and grass out of the cooling find on the cylinder jugs..you do this to keep the engine running cool
I have both a 16G and 20G in my collection.
20G is 1992
16G is 2001..
2021 and both are...
The 5240 has a mechanical diaphragm fuel pump however it may run with just gravity flow and may stutter if it doesn't have pressure from the pump.
I'd check it next
Also make sure the governor is adjusted properly..
I have a 5260 in my collection..it's the same K181 set up but with electric start..
The downfall of carburators on old tractors-motorcycles and the like is alcohol contaminated fuel..
Clean the carb in a parts cleaner using purple magic cleaner..
Then use alcohol free gas..