Is this true? I hear so many horror stories about piston failure after the installation of a Wiseco that I would be reluctant to install one in my machine if a new piston was required.

Is there anybody out there that has bought just one of these and then drove happily ever-after for thousands of miles?

You must be hearing from some liars. I've only heard good thing about wiseco. I think they are the best pistons you can get, Of course I haven't put too many hours on my new wiseco top end, but I do feel they are the best. Especially the pro-lite series.

Ive wasted three of them on my 85 quadracer. Dont know if I did not let it cool down enough while breaking it in, but what I do know is that im not going to buy another Wiseco..

RoostKing...

My wiseco pistons (banshee) have been running strong for 2 years now. Of course I don't race on a professional level.
But these pistons have seen some district 3, ny action and plenty of practice track and trail time. I also have a habit of jetting and mixing fuel a bit on the rich side to prolong life a bit.
I think most of the horror stories you hear are do to people running there bikes right on the edge (lean jetting) for the most power output. If you are careful...jetted properly and running the proper fuel mixture...you should be able to make it for a while before a rebuild.

pistons are sort of an opinion..everyone has their favorites, when in fact most work great. I've run Wiseco, Pro-X and stock, the only difference being Wiseco runs a bit more clearance and requires a definite break in period..Pro-X and stock are cast pistons, and don't expand as much.

Wiseco pistons are fine but you have to run larger tolerances with them because they are forged and forged pistons expand faster than a cast piston like Pro-X or a stock Sudco/ART.
If you warm the engine up correctly, there should be no problems. A stock 86 250R piston is only a couple of grams heavier than Wiseco. This might be an issue for someone who wants to get every little amount of extra power out of their engine, but for most of us it is not an issue.
ERIC

The biggest thing with a Wiseco piston is to let the engine warm up before you hammer on it...
Put your hand on the coolant hose and feel that the engine has reached temp.
Also, if you're running a two stroke with modifications that require more than a couple of jet sizes with oil injection, add some oil to the fuel to keep everything lubed up.

First off is break in. I have broken my banshee in for 10hrs. before I really full throtteled it and held it. I started out with 1/4 throttel for 15mins 3 or 4 times. Next you go 1/2 for like 30mins, for 10 hours. Also I had to let it cool totally off once it heated up. Now that it is broke in, I have to make sure it is warmed up and ready to be opened up, this is called a cold seizure I think. I have wiseco's pro-lites which are bought in a kit and balanced, and so far they are fine and work great.

What I don't understand is why these pistons are popular, are they light weight? come in sizes that the OEMs don't or what? They seem to require extra special care and tolerances to perform as well as regular cast pistons. Is it the price?

Wiseco pistons are slightly lighter than stock. OEM pistons are usually only made to about .020" over.
Wiseco, and other piston manufactures make much larger pistons in most cases. You can get .140" over for 250R's and they make larger ones for big bore applications.
Prices are not that much different either.
ERIC