The cases will not split!!! Help

[Conrad#356]

I need to replace the crank on my 05 yz125 and Im using a crankcase seperating tool. I've got all of the stuff on the right side of the case removed.(Primary Drive gear, Clutch, All the shift mechanisms). Ive tried connecting the case splitter to both side and it just won't come appart. I can see that the glue is broken all the way around because it starts to open up but at the front of the engine it stays closed. Please help, I need any tips!!!

[dellaquila]

There has to be a bolt still tight somewhere. Have you seen the videos RMATV has on Youtube walking you through a YZ250 bottom end rebuild? They're in a few posts on here now too. Watch those and see if you're missing something.

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Hope those help!

[Conrad#356]

Originally Posted by dellaquila

There has to be a bolt still tight somewhere. Have you seen the videos RMATV has on Youtube walking you through a YZ250 bottom end rebuild? They're in a few posts on here now too. Watch those and see if you're missing something.

[Only registered and activated users can see links. ]

[Only registered and activated users can see links. ]

[Only registered and activated users can see links. ]

Hope those help!

The manual says there is only twelve bolts and I removed twelve bolts. I'll tell you though, its pretty frustrating when you buy a case splitter and the cases won't split.

Does anyone know if heating up where the cases meet helps them come apart.

[JDR215]

im not too sure with the yamis, but on hondas there are a couple of bolts inside the stator cover on the left hand side of the engine, sounds like bolts are still somewhere to me.

[psycho393]

The cases should just about fall apart if you have all the bolts out.

[Fireman87]

You have to take the flywheel and stator plate off as well (atleast on my honda's you do) And like they said above when everythings out i don't even need a case splitting tool i can grab ahold of my jug bolt stuts and pull a little bit and the'll start to come apart where i can stick my fingers in between the cases



Other than that, good luck hopfully you can figure it out.. oh and I don't know if you have a manual or not but buy a Clymer manual, one of the best manuals imo for tear downs and putting it back togeather, has detailed descriptions, pictures and torque spec. charts.

[Conrad#356]

I got the three bolts in the stator. I have the stator and the flywheel off. I also have a manual but I don't know why they won't come apart. Somebodys had to of had this problem before!!!

[crfjedi393]

Originally Posted by Conrad#356

Somebodys had to of had this problem before!!!

Yep. But it's ALWAYS been because I was overlooking one last bolt. Keep searching.

[mark 1987 930]

Did yo try light taps with a rubber mallet while your put some tension with the case splitting tool?

[Conrad#356]

Originally Posted by mark 1987 930

Did yo try light taps with a rubber mallet while your put some tension with the case splitting tool?

I have tried a rubber mallet and I pretty positive that I got all the bolts, I took off twelve and thats all theres supposed to be but I'll check again.

[crfjedi393]

Get a flashlight and check everywhere inside and out. I've only split CRF cases but there are some bolts in not-so-obvious places.

[JDR215]

it is a yamaha............




hope u get it man, without smashing it to bits with a sledge hammer.

[mark 1987 930]

If you are 100% positive that you've removed the bolts holding the cases together, how hard are you turning the case splitter tool? IF they've never been apart, chances are it'll be tough the first go around. My KX made a huge poping sound when it first split.. I was worried at first that I stripped the threads.. but no, it had finally came undone. It's a tight pressed fit between the crank, bearing, and case. I had to continue to use the splitter to seperate the cases completly.

When you stated you saw it split, how much was it? a hair, 1/4inch?

[Conrad#356]

Originally Posted by mark 1987 930

If you are 100% positive that you've removed the bolts holding the cases together, how hard are you turning the case splitter tool? IF they've never been apart, chances are it'll be tough the first go around. My KX made a huge poping sound when it first split.. I was worried at first that I stripped the threads.. but no, it had finally came undone. It's a tight pressed fit between the crank, bearing, and case. I had to continue to use the splitter to seperate the cases completly.

When you stated you saw it split, how much was it? a hair, 1/4inch?

It was only like a hair but it sucks right back down. The back will split like a 1/4 inch with my hands

[Conrad#356]

Thanks for the help guys. I finally got it to split. There wasn't any bolts left but I made a nifty little engine stand for it so I could really crank on the splitter and it made a huge pop and then it came apart. I got The transmission out and everything. It seems that the crank wasn't the problem at all but one of the case bearings was really rough so I guess it won't be as expensive as I though it would be.

[Conrad#356]

Oh and I'll try and get some pics up if any one wants to see anything. Tell me if it all looks good.

[mark 1987 930]

Congrats.. When mine poped.. i just about my pants.. I thought I had stripped some thread or something.. That's why I wrote it in my previous post. I had to turn the splitter pretty hard to get it open.
I'm jsut waiting for parts to put mine back together now (transmission input shaft split in two..).