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Hows it going boys, long time noo talkk, feel bad i havent had much time to make it on here, been working on lots of stuff. right now i have a project 1991 yz250 on the go. the bike is in boxes and im putting it back together and restoring it very slowly. The crank on this thing is good. Spins nice and no play in bearings. What i would like to do it take all the bottom end apart regardless because it has been sitting so id liketo clean it up. Ive read over my manual and watched numorous videos about this, doesnt seem like the simplest job in the world but i think i could pull it off. What im mostly worried about is all the specialty tools i need to do this, fly wheel holder, clutch holder and crank puller. I was looking for someone who has done this before. Is it worth doing by yourself? or should i just send it away?

Thanks

James
 

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IMO you should send it out. They're a PITA.
 

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gettin bored of that 4 poke already James? [beatup]

anyways, id send it out. spendy but worth it in the end. you wont have that thought in the back of your head of your bike breaking because you did something wrong. lol
 

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i disagree with the above. do it yourself! its easy but time consuming. The only tricky part is if you take the tranny out... its easy to take it back out but a pain to put back in. I split the cases on my 92 rm250 without a case splitter but you will need a crank puller to pull the crank into the bearing when your putting it back together. you also need a flywheel puller (ill sell mine). no need for a flywheel holder either, just impact the nut off
 

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I have had many bottom ends apart on quads and bikes. Its kinda my specialty.... If you decide to do it yourself first thing you will need is a manual for proper torque, proper part fitments etc. The biggest thing is to take your time...there are a lot of small parts that are vital to the proper operation of the engine and transmission. You need to be sure that you get them in the right place and in the right orientation.....spring washers, bolts and such.

The bearings have to be pressed in and out.....and as said before you will need the crank puller to get the crank in the bearings. If you are not replacing the crank bearings(I do it regardless when I split a case) they will more than likely stay on the crank and you will not need the puller. My question is did it run before? If it shifted good(nice and firm)and stayed in gear and the crank bearings are good I wouldn't even tear it down. You can clean it with mineral spirits or gas just make sure you get it re-lubed right away. As far as the "crank" case on a two stroke it is completely blocked off from the tranny and you can pretty much look in there and see what it looks like. If you want to change the seals you can do it with a sheet metal screw and vice grips. If you have any questions pm me I have done the yz250 before....

I'm gonna get beat up on this one but a big modern day 4 stroke bike will light a two stroke up any day. But with a match in cc's 250 vs 250 the two strokes almost always win. Most 250s 2-s are pretty fast but take a crf450 or yzf450 and it will leave it sitting. Yeah you have more cc's but back in the day the 250s would eat just about any(if not all) four strokes up. Now if you tune the two stroke.....thats a whole different story
 
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