QUOTE=JetMD;4406164]Changing only the rear is kind of a pain without a puller. The reason being that when you change both, you can easily punch out the front which will give you room to get a punch on the rear one. If you leave the front one in, you have to use a small punch plus, the angle of the punch through the hole in the front bearing to the rear bearing is very steep and you won't get a very good hit on the rear one. I know this from experience. So, without a puller, it is much easier to just go ahead and remove the front one first, then punch out the rear. If you can afford it, might as well change the front one too because you're going to have to knock it out anyway.
What I do is pull everything off the motor, including hidden o'rings down in the carb. throat area. Then, I put the new bearings in the freezer. Then, i'll heat a toaster oven up to about 400 F and put the motor in for a while. I don't know how long exactly, maybe 5-10min. Then i'll use a punch and hammer to knock out the front one, and another punch and hammer to knock out the rear. I'll put it back in the oven for another couple min. to get it warm again. Then i'll get the bearings out of the freezer and i'll usually put the rear one in first using a bigger brass punch, and then i'll put the front one in.
Heating and freezing may be overkill, but that's how I was taught and it always works like a charm.[/QUOTE]
Well actually the engine is brand new its a picco evo 9 .21, i have one gallon of fuel through it, guys tell me thats common with the picco motor, the rear bearing is the first to go, plus me needing to store it in a better climate controled area...but the front bearing kewl..