Two Stroke Motocross
Two Stroke Motocross Forum => Technical => Topic started by: cman on June 05, 2011, 11:48:40 AM
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Guys!
I just found out that the main bearing ceased and I'm in the process of getting everything together. One question came up so far....... The manual is requiring a special tool to install the crankshaft on my 2006 RM250. But I have talked to some people and not too many actually uses this tool. Other method has been done successfully without it. I'm wonder what the common method you guys use when installing the crankshaft?
Thanks!
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I used a puller tool:
(http://i610.photobucket.com/albums/tt188/citabjockey/SC500/IMG_0887.jpg)
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Crank and main bearings in the freezer. Case in the oven at 200 degrees for twenty minutes or so. Install the bearings, then put the case with bearings back in the oven. The crank will pretty much fall in place. If you are quick with the tranny install the whole assembly is very easy. Even if it takes awhile to get the tranny in correctly I have found the second half generally goes on the crank much easier then the first side. I have done a dozen bikes this way without issue. And if you do a search on other sites you will see this technique is fairly common for bottom ends.
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I would go with Coop's method.Pullers are fine but you have to be careful as you can exert a lot of pressure without realizing it.
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Thanks guys! Sounds pretty easy but I know it will take some practice....I guess I'll try to practice putting the tranny assembly in correctly and quickly as possible.
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yes, I have done Coops method a number of times also and it works perfectly. It is also good to do all of the work right there on the kitchen table if the wife will let you get away with it!!! ;D
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It is also good to do all of the work right there on the kitchen table if the wife will let you get away with it!!! ;D
Or just do it while she is at work...Hehe:
(http://i47.photobucket.com/albums/f190/SVCoop/Bikes/KX125/Crank-3.jpg)
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Great kitchen photo.... and I see you also have her trained (or de-sensitized to the horror in her kitchen) well! It is clear from this photo that there is absolutely no possible way to collect the parts in a box and get them out of the kitchen in the mere seconds available from the time you hear her car door shutting in the driveway!
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LOL yeah that would have been a trick for sure.
Seriously she knew I was doing this. A couple winters ago I was rebuilding a KX125 and it was COLD outside and I was out of heating oil in the garage. But she is used to it, many years ago when we first got together we lived in a small dumpy mobile home without a garage and I completely refurbished a 1984 KTM125MX inside over a winter :D . The only thing I didn't do in the house was paint the frame and other parts. We did those at my brothers house. I don't know why she puts up with me...
Here is some photo evidence of the KTM build and them I will stop derailing cman's thread :) .
(http://i47.photobucket.com/albums/f190/SVCoop/Bikes/KTM/10.jpg)
(http://i47.photobucket.com/albums/f190/SVCoop/Bikes/KTM/5.jpg)
(http://i47.photobucket.com/albums/f190/SVCoop/Bikes/KTM/Ktm15.jpg)
(http://i47.photobucket.com/albums/f190/SVCoop/Bikes/KTM/Ktm11.jpg)
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Great stuff guys!!! I think one of the best parts of a rebuild is the story behind it....specially the "where" and "how" it was done.
Now on to my shopping list....new bearings........new crank..... butanes and a used oven...lol!
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LOL. Awesome. Remember feel free to ask any and all questions. We all started somewhere so don't be shy about questions. Plus take pics and post them of your progress.
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cman, just a note on the parts... most, if not all, of the required bearings and seals can be purchased at your local bearing supply store. The bearings are industry standards and there is no need wait, special order, etc, etc for oem parts if they are not available at your bike shop. If you need to, take out the old and the shop will measure them up for you and get it sorted out with the correct replacements. just make sure you buy the quality stuff because the shop will usually have a selection of brands to choose from.
Great photos Coop, I can share that mine is also understanding since I have done the bottom end 3 times now on our kitchen table... she does get a little nervous tho when we bring out the rubber mallet and start "adjusting" things!
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Last year I helped a friend redo the bottom end on his KX 125. It was the 1st time either of us slit the cases on a engine. We replaced the crank, bearing, water pump, seals, etc. It really wasn't too difficult. So this past winter, I replaced the crank on my son's Honda 400EX. Yes its a 4 stroke, but the bottom end is basically the same, except for some seals. Itâ??s really not too bad if you take your time, and yes you'll need a rubber mallet for some gentle adjustments.
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Suzuki is bad for using odd ball sized bearings and seals that aren't usually stocked by bearing dealerships.
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All you can do is check the shop. All of my bottom end rebuilds were for rm250s ( 2000, 2004 and 2006) and the bearing shop had everything. I live in the Middle East and things aren't so easy to come by out here most of the time. In any event keep us posted on how it goes.....
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Still waiting on parts....Man!! Another week before i get them. None were in stock and had to be ordered from Suzuki.
I guess that's okay since I'm fiddling around in putting one of the transmission shaft together. It sorta came apart when I took it off :-[ If I only knew how confusing it is to put the washers back in order....i would have been more careful. Oh well! I have the manual but it's better to bring it up on a monitor to zoom in better.
On the other hand though...I'm getting really good at cleaning the parts. Now I see why people end up painting or polishing their cases.
Thanks Guys!
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I use parts fiche mostly for transmissions and such. I just print the fiche out and have it with me at the bench if I get stuck. Once you do a couple it's less intimidating LOL.