splitting cases

[cr250]

How hard its it to split the case on a 96 yz125?? I can rebuild the top end, have rebuilt my clutch basket and etc...but I have never split my case...Now due to some random loose bolt in my tranny I'm either going to have to split the case or have a shop do it...I don't have a magneto puller but I can get that off ok I think with tire irons and a dead blow hammer...I'm not sure about the water pump or what happens when the case is split...like which side should be down (the clutch (right) side or the shifter side...??? Any info would be appreciated.
thank you very much!!
vanessa

 

[Rockey5000]

There should be a pry point on the cases, get a service manual it will help greatly!

 

[cr250]

ok but which side can I set it on to remove split and remove the top case easily w/o dropping anything...Thank you!!!

 

[Rockey5000]

Im not sure on a CR but when I split the cases on a Mojave I set it clutch side down and used the pry points to open it up. Its not really that tough, you should be able to do it.

 

[cr25096er]

pry points? do xr's hjave them? splitting them isnt hard but time consuming.

 

[Layton]

Originally posted by cr250
I don't have a magneto puller but I can get that off ok I think with tire irons and a dead blow hammer

If you try taking the flywheel off like that you will have more to worry about then just splitting the cases. Get the proper flywheel puller from your dealer before you ruin the flywheel and or crank end. :(

While you are at the dealer getting the puller also pick up a service manual for the bike. You will need it to figure out where all the shims etc. go that fall out of the case when it comes apart.

Actually once the flywheel is off the rest is usually fairly easy. Just take your time and CAREFULLY tap the case until it comes apart.

Good luck.

 

[cr250]

Lol I tried many times to get the puller...Everyone I've talked to has told me that it isn't made...I tried Yamaha...and several local dealers...their computers didn't recognize the part # in my manual...no lluck. I have a 96 yz 125...the magneto has been taken off pretty recently so I think I can get it off this way. What do I have to worry about as far as damaging tings?? I definently don't want to screw anything up...and I have the original manual for the bike and have been reading it quite a bit before i get into this lol...I really appreciate the help and am cracking it open today so I'll let you all know how it goes :)

 

[DEANSFASTWAY]

Get the right puller vanessa thyre cheap and are available aftermarket from motion pro or through Dennis Kirk or JC whitney parts unlimited tucker rocky etc That same puller fits almost all Jap @ strokes . You should also get a book while youre there so you can see how tghings come apart and what to torque bolts to. As for splitting the cases the gears usuall stay attatched to the R/S case and the crank usually stauys stuck inthe left . Dont remove the shifter ratchet mechanism unless you really have to becase that and the shifter forks will help keeop the trans together when disassembling Large rubber bands wrapped around the case R/S and trans will help hold the assy together until you are ready for that step. But that is where your problem is in the trans , right? As a beginner you really shouldnt attempt this without a manual or a friend that has done this before , plus the manual will tell you what to look for. When reassembling the cases it might help to lat a droplight on the open bearing side to help let the crank slie in also a little oil on the shaft . New crank seals and maybe main bearings might not be a bad maintenance investment right now also ,(theyre cheap while you have it apart). Use good motorcycle sealer on the case halves Yamabond or Hondabond or Threebond brand is good stuff . I have had many many of these YAMS apart and have seen parts of the shift mechanism R/S screws springs detent things etc come loose . Also I think there may be a small plate that hold bearings in the trans that maybe the screw has backed out . You could probably do this yourself just get the right stuff so you dont hack it up .Take it slow. GOOD LUCK

 

[bruce j]

I can't believe these dealers wouldn't be able to get a puller for you. It doesn't sound like they tried very hard. I would bet they all have one in their own shop. If you take the engine in to them with the ignition sidecover off, it's about a 2 minute job to get the flywheel off, would probably cost less than buying a puller for yourself. Of course ,if you buy one, you'll have it for next time. If you try hammering or prying it off, you risk breaking or bending the flywheel, crankshaft, and cases. Good luck!

 

[fisha69]

Does anyone know how long it takes to get to the oil seals in the crank case? About how many minutes does it take (YZ125)?

Dave

 

[70 marlin]

In the back of my manual they have a spechial tool section. buy the right tool's! DEANSFASTWAY pretty much gave the right answer! do not pry on your case unless you want new ones. put the right side down. use the correct tools be very gental, and most of all rememeber or write down where you remove stuff from! even manuals don't help much when it comes to putting it back to gether. maybe even take some close up pictures. use a seprate sandwich bags for each section you remove. that way stuff stay's seperated! good luck

 

[cr250]

Well the magneto came right off but the case won't come apart and I'm not sure about how to split it so I'm gonna have a friend help me. So far everything has been easy and the manual which I have always had since I got the bike seems to be right on. I don't have a case splitter but my friend does so I guess I'm ok there...I just did a bottom end rebuild in Fla with a friend of mine so the bearings and rod and seals are all new...unfortunately I was working on my swingarm bearings when he split the cases :| and I'm in Co now so I can't really get him to show me how he did it. . :(:( Well I guess it'll work out... thanks so much for all the info:)
Later
Vanessa

 

[Layton]

How did you get the flywheel off?

 

[cr250]

The magneto I just popped off with two opposed tire irons and a rubber mallet (I used a rag under the irons so there would not be any damage the case gasket surface)...I just got it back from a guy who split the cases for me and it seems to run great there was a loose bolt that had scuffed part of my case and needed to be replaced/removed but no real damage :) Going riding today finally :)
V

 

[Birken Vogt]

Score another one for backyard-style.

I don't have a press or pullers either but with a vise, hammers and screwdrivers I seem to get everything done. The trick is to have experience working with the stuff beforehand so you can know how far to abuse it before saying "this is gonna break it" and then buying the real tools.