I also was wondering if the 225s will fit on my 2005 1707 Hi Lo since it is a single axle ?
You have almost the same trailer as me. Mine's a 2007 version. 225s would NOT fit on my trailer in its "stock" condition. The clearance between the tire and the step frame on the curb side was too tight. I think the top clearance in the wheel well was too tight too. 225s have, if memory serves, about a 2" larger diameter and are about 1" wider. The width is not a problem, but the larger diameter is. The 225s also take wheels that are 6" wide as opposed to the narrower stock wheels.
I had my axle moved forward three inches, because the tongue weight was more than 600# and the clearance between the tire and the step frame was only about 1/2". At the same time, I had a 1-1/2" spacer put in between the axle and the frame it mounts to. This gave me much more clearance all around in the wheel wells and allowed me the room to mount the larger tires (and wheels). Overall, the trailer now rides about 2-1/2" higher, getting the water tanks away from the road surface. And, with the axle forward, the tongue weight is between 10-14% of the trailer weight (depending on trailer loading).
The only potential problem was that the tire could come in contact with the cable bolts on the left side. They were cut shorter to provide clearance. This would only be a new problem if I needed to lengthen the cables, which I cannot see having to do.
Moving the axle cost me $400 at a local welding shop that I trusted - they do work on County fire department vehicles that are driven off road in the Tucson area.
Your OEM axle/tire combination in your trailer are rated at 3500#, less than the 3800# max gross weight. I personally feel this is an unsafe design. With my new D-rated 225s, I've gained a significant margin of safety in the tires and have had no problems whatsoever.
Hear's a link to the "saga" of my axle reconfiguring:
http://www.hilotrailerforum.com/f26/my-trailer-overloaded-412/
- Jack