Anyone know a source for 13 1/8" replacement blades? I'd like to stick one on a 12" saw that I own to get a little bit more depth out of it. I also thought about putting a 9" blade on an 8" saw for a bit more depth.

I suppose you are aware of the associated issues with putting the wrong sized blades on saws. It is worse with too small of blades which will spin too fast and overdrive the motor, but too large of blades will also wear it out faster, and also the obvious issues of guards and the saw body not being sized to fit such a blade.

With all that in mind, feel free to do what you want with your tools. It's just good to be aware of the potential problems. I often modify or 'overuse' tools, it just happens some times. My power tools frequently get used for things they weren't designed for!

If we followed the directions all of the time, we'd never have any fun! How many builders out there have never pulled the guard back on the saw before making a cut with a circular saw, or made a plunge cut? I think there's room in both saws for slightly bigger blades. It would be really nice to get 3" of depth on an 8" saw.

certainly! It's just some times the 'improvements' people make to their tools just make me scratch my head.

I remember on a job once where one guy had a 12" circular saw that he had completely removed the guard from, and it had no brake on it. That thing gave me the willies to say the least.

If there's room, go for it! Just be aware that a bigger blade and deeper cut will load the motor a whole lot more, which will eventually burn it out, or require some brush replacements. Bigger saws have bigger motors that are set to spin at appropriately different speeds. I have burned out router motors for example by using bigger bits than the router could handle, a bigger blade is the same general idea.

it sure is one of the first things I did to a cheap'o Hitachi saw when I got it.
Keep in mind, Makita uses the same motor on both the 7.25" and their 8.25" saws, Bigfoot uses the wormdrive skill body/motor for both their 10.25" AND 14" saws, so you should have enough power to push the blades you're proposing. Bigfoot might also be the only source for a 14" blade for your 12", I don't think anyone makes a 13" blade.
here's my hitachi set up with a 8.25" blade, some trimming required

Tenryu blades (which are excellent) may have one. And if the arbor is the wrong size it can be easily bushed or drilled out.

I must try a 8-1/2" blade on my 8-1/4" saw, it is a bugger when the brace stock is a little heavy and the saw doesn't make it all the way. I hope it clears everything.

I also realized why your eyes water when it is extra windy and cold, the flushing action helps the sawdust wash mostly out of your eyes.

Glad to see I'm not the only one with a penchant for getting a bit more out of tools. I always assumed Bigfoot geared the motor down. Seems like it would be an utter necessity for the 14" one. What kind of surgery did you do on the hitachi to squeeze in a bigger blade? Does the guard still work? Personally, I view the guard of a beam saw as more of a convenience. It lets you set the tool down on the ground without having to wait for the blade to stop spinning and keeps the blade out of the dirt. I don't think I've ever had a big saw kick back on me. Usually the problem is the opposite-- the motor bogs. Maybe I'm just young and dumb, but I'm inclined to think "safety" can sometimes be a bit overrated. We all draw the line somewhere.

not sure about gearing on the 14", but I noticed it comes with a whopping 1 month motor warranty..

the 'tachi only needed some notching of the base, none of the housing itself. Not sure about the guard, none of my saws have them.

Timberwrestler-- I've got an old Rockwell 10" saw that has a 3/4" arbor. Since standard 10" blades have a 5/8" arbor, I've reamed out the last two blades I've put on it with a tapered reamer. The blade steel is so hard though, by the end the reamer has usually had it. Plus, this being a "by-hand" operation involving removing a fair amount of metal, the hole inevitably winds up a bit off of center. Just enough to cause a very slight but noticeable vibration. What I need to do is get a 10" blade (maybe from Tenryu) w/ a 1" arbor hole and bush it down to 3/4".