No, you should have a battery in the tractor to run it. Without looking, I think you have two posibilities on making up some tension on the belt. If it has an idler pulley quite close to the engine drive pulley, the mount bolt goes through a slot in the frame and is adjustable. There are two idlers towards the rear. I'm thinking that th rear of the two are adjustable as well. Adjust to the point it works well. I THINK there is a spec on the compression spring on the clutch rod of an 1 1/4"

I can't attest to the difficulty of the mower/loader changeout since I own a later model 445. The mower decks mount in a similar way though, and it's a straightforward process to take the deck on and off. Someone with a 420 loader would have to answer about the ease of install for it. The Onans (probably P220 in the 420) had a life expectancy of 2000 hours I believe, but things to break and finding replacement parts can be a bit of a challenge to say the least. The loaders on these big GTs are stout enough to dig with, but how well you can dig depends greatly on how difficult your soil conditions are and how much ballast you can hang off the rear of the tractor to give it enough traction and mass to keep the bucket going forward. I have clay soil and when it's soft enough to dig I get wheelspin and when its hard enough for good traction it's a bear to break it oiut.

I just wanted to post MY CRAFTSMAN HORROR STORY HERE....I bought a 15 1/2 horsepower 42 in cut from sears about 7 years ago,the first problem was probably the second mowing, i hit an apple mowing under an apple tree and it bent 1 of the blades lol.Next thing was the screws kept comming loose "everywhere",then the mowing belt broke,and the steering -sheeesh ,, hit a bump,touch a fence post,get it in a bind and the steering strips and keeps striping,there's not much you can do for that sucky kind of setup,and the steering rod fell off several times...next i noticed it was getting hard to crank and didn't have much power - i noticed the head gasket was leaking because the head bolts had came loose, the gasket was burnt into so i got a new 1,about a week later it stopped running,,turning the motor you could tell it didn't have any compression so i removed the head thinking it was the gasket blown again,,,but noooo wow 1 of the valve seats had popped out of the motor holding the valve open,, i used jb weld to stick it back in,,somewhere along the way the rear end went out and i replaced it,,other than that it was great! In 2004 i bought a murray 15 1/2hp O/H valve 42in cut mower ... all i do to it is add gas,change oil and mow. I do have an older murray stripped down into a riding machine,best tool a small farm can have for hauling small loads and going out in the fields.

thanks to all above for input. i think the heaviest i will be towing is a cartful of cedar mulch. although john deere has a 10 cu ft cart for the 304, i was thinking about getting a 16-17 cart mostly so that i avoid having mulch or any loose load spill over the sides...i'll be sure to try and estimate the load to be less than the tractor as engine tech's explanation makes good sense engine tech, curious about keeping the throttle up during towing. this decreases the work load on the transmission?