Wow!

[Six Stroke]

I got my YT175 pipe in the mail Thursday, and I put it on the 125 yesterday. Wow!
Quite a noticeable difference! There are some jetting issues to sort out now, of course. If you've ever tried to rip through the gears on a cold dirt bike, you'll know that it really doesn't start to go until you get up in the higher gears. This does the same thing. She comes on a lot stronger than it used to midway through 3rd gear.

I can't wait to get a 175 carb and some Boyesens on it!

[short4stuff]

Sweet bring back the ol' 125, next thing after the carb and reeds... get a 175 topend

That would be a blast.. make sure you get atleast front suspension though

[Six Stroke]

Installation was a snap. Aside from having to use the 175 cylinder-to-pipe adapter, the rear mount was the only thing that didn't jive. All I did was weld a 4-5" piece of strap steel to the mounting ear on the pipe, and had it come straight forward to the stock 125 frame mount. Then I drilled a hole and bolted it to the frame mount. It was the best $9.90 + shipping that I've spent on it!