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2002 RM125 build help tools ? What do I really need

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Ok so I am new to this forum and it's because this is my first two stroke rebuild. So sorry if theses questions have been answered. I am a back yard mechanic and have done car motors but no two smokes. 

Bike history: purchased running like crap claiming it needed carbs. Did carbs and it ran like a raped ape. I foolishly had to take it out on the coldest day of the year not let it warm up and seized the crank. The piston was on the way and the cylinder had a little wear and had to be honed and replayted. So it leads to the following ...

Parts in rebuild to be installed 

wiesco piston,hot rods crank + bearings, all case seals, la sleeve 

I have had the cylinder sleeved and am ready to start getting the tools I will need. But have hit the following wall. I have come to the conclusion that in the repair manual it asks you to use two tools one is $800 and the other $500.

so my question is how many of these tools are absolutely nessiary to complete the job. I have purchased the two items below. i am stuck here. 

Tools the books says I need : 

09930-40113 rotor holder

09910-32812 crank installer -purchased tusk

09913-50121 oil seal remover 

09920-13120 case splitter - purchased tusk 

09913-70210 bearing remover installer ?

09921-20220 bearing remover ?


Any help tips or tricks would be much appreciated. If you need more info let me know and please tell me if I missed something or am wrong about something. 

Edited by Rm125o2

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You don't really need a seal remover. Normally a threading a wood screw in and pulling it out works fine. If you do plan on removing the bearings in the cases and putting new ones in I would recommend bringing it to a shop or getting a buddy to do it. And for that roter holder you could prob get away without using it but it would be handy to have. Here it is on ebay for less than $90 shipped. 



And yeah just looked up this one 09913-70210 bearing remover installer. You definitely don't need it. I would say people normally use a hydraulic press to remove the bearings and then often heat up the cases in a oven and freeze the bearings and they drop in. Or just bring it to a shop. 


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You don't need special tools to remove and install bottom end bearings, but you do need to implore a few techniques.  To remove all the bearings, stick each case half in the oven, heating it up to about 250f, or a little higher.  Water should sizzle when dropped onto the case.  Once hot, pull it out and tap it straight down onto a block of wood so that the shock causes the bearings to drop out.  Don't hit it too hard, as the metal is hot and slightly soft, and slightly more prone to damage.  If you encounter a stubborn bearing, have a few tools on hand that can help you to tap or pry it out while the case is still hot. 

As far as installing new bearings, again place each case half in the oven, heating to about 250f.  Place the bearings in the freezer a day or two in advance so they will shrink as much as possible.  In a very quick fashion, remove the bearing from the freezer and drop it into the freshly baked case.  It will still be a very difficult fit, and messing it up can cause it to get stuck in a crooked position, but if you place it in very squarely, it should slip into the hole.  Keep a soft mallet on hand to help persuade it a bit if needed, but if you have to hammer it too much, you'll just be messing up the bearing and the case, and you're better off starting over.  

Bottom end bearings are the most frustrating part of two stroke work, in my opinion.  Just be cautious and take your time so that you don't end up doing more damage (to your cases) than good. 

I also own a 02 RM 125.  If you're looking for more hp, my favorite mods have been the pc pipe mated with the pc 304 (long version, not shorty) silencer, and running the boyesen RAD valve.  I also milled about .2 mm off the head.  Mate all this with a 51t rear sprocket (keeping stock front sprocket), and the bike has a very easy to access and powerful mid with great pull all the way up.  Gutless down low, obviously, but a very good 125 feel.  

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