Procedures for removing & replacing rear engine bearing .21 picco.
 

Need to know how to remove and replace rear engine bearing.:tire::tire::tire:

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=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..:tire::tire::tire:

Turn your oven up to 500 and heat it for about 5-10 mins like the other guy said and it should just about fall out. Worst I have had to do is tap lightly on the sides with the plastic end of a screwdriver. When you heat up the aluminum case it will fall out when heated enough.

bearing
 

step 1) disassemble engine, you need to get to the bare block.
step 2) heat the block with a heat gun or oven to 250-300 degrees for 15 minutes.(make sure the block doesn't get hotter than 300 degrees)
step 3) while the block is heating up, prepare the NEW bearing by sliding it on the crankshaft ( be careful that it is facing the right way!!)
Next steps you have to do it fast because the block gets smaller as it cools.
step 4) grab the block with a rag (be careful it's very hot) and tap it on a piece of wood block or board with the rear case opening facing down, and the bearing should drop down.
step 5) drop the crankshaft w/bearing down into the opening and it should align itself perfectly as the end goes through the front bearing.
step 6) pull the crank as hard as you can so the bearing goes in all the way and sits flush. If you want (if the block is still hot) you can install the flywheel/collet and nut and as you tighten it will pull the bearing flush into the opening.

then you let the block cool down and reinstall everything.

My toaster oven doesn't go to 500. From what you're saying, I wish it did! :lol:

It is not a good idea to heat the Crankcase pass 300 degrees anyway, you will risk melting/deforming the plastic ball retainer on the bearing which will cause the bearing to seize. the best way is to use a Quality engine bearing puller and installer when replacing the engine bearings, pullers and installers made by JP racing or RB are amongst the best.

Thanks for the info guys, very valuable information, i appreciate it, i'll let you guys know how it went, thanks again...:nod: