Re: Converting Trailer Tires, 12" to 8"
The problem is that he's dealing with a trihull, there's not many trailers made that will fit that boat well. The chances of finding an affordable used trailer in his weight class may be tough. I all but ended up custom rebuilding mine to make it work.
Mine was originally set up with strait axles under the springs, I built two axles and mounted them above the springs. I also have the option of going from 13" to 12" wheels if needed. The trailer sits pretty low after flipping the axles, which were made from 2x2" tubing with no camber.
I also ordered flatter springs, which gave me another 1.5" or so. Over all the boat went from sitting 33" above the pavement in tow to being about 22" off the ground. That made a huge difference at the ramp. I also added a longer tongue, I went from about 12" ahead of the bow to about 42" up front. Being a welded, painted trailer, I just cut out the old tongue and welded in a new one which was longer.
Keep in mind that those outer hulls will interfere with most fenders if he goes with a common curved cross member trailer and fenders can come really close to the hull sides if they are wide enough to clear and happen to end up next to the hull when loaded.
I found that on most trihull boats, a flat trailer is the best option overall, the lower you can make it all ride the better but it's not likely going to be as low as a V hull on a proper trailer.
Drop axles make for the best set up, along with high capacity smaller tires, but that usually means building or customizing your own set up. I did see one guy running a tandem axle trailer with 16.5" x 6.50 x 8" wheels and tires which were on a flat frame trailer with drop axles. It got the boat low enough where he did need to run with the motor fully tilted.
What make is that boat? Starcraft? Many of those older trihulls weren't that heavy in outboard form. My Capri 17 is light enough that I can lift the hull off the trailer by myself with little effort. They are light hulls if they're not water logged.
.......... The boat ramp is about 12 miles from my house, drive about 40-45 mph when towing. Just replaced all the wheel bearings and I use the best grease NAPA had. (another tip I picked up from this site).
