89' RM 125 Crank Removal

[egmike]

I recently pic'ed up a 89 rm 125 that was supposidly rebuilt on top and bottom end but got 2 hrs on the trail and 2 miles in and the bottom end let go!
I am now trying to rebuild it now, cylinder is has been sent to get bored out for new piston and ring and have gotten the case split but the crank is stuck in half the case ! Just wondering if you have any suggestions to get it out. hitting with a rubber mallot doesnt do anything, and I dont wanna crack the case, the other side came out with ease.

Still not sure why it failed, was really gutless down low but wasnt sure if that was normal with this bike or not, I was told that 125's were so didnt think much of it

 

[egmike]

I'd post a pic but cause I am a unable to post link

 

[NacNac250F]

Use heat and a press and it will come right out. Put something over the end of the crank that our pressing on so that you dont mess it up. If you don't have acess to a press then go get a nice dead blow hammer, using a mallet is no better than hitting it with your hand. THe crank usually does stay in one side of the cases. If the bearing comes out with the crank then you'll need a bearing puller that fits behind a bearing to pull it off.

 

[egmike]

Heat and press it out heh - I kinda figured it would need that.

I dont have access to a press so I am gonna take it all down to local bike shop and get them to do it, they have to get the crank pin pressed out anyhow to replaced the bearing & rod

 

[MXP1MP]

That rubber mallet isn't the right tool you need like a plastic mallet to hit it with aka dead blow, all the rubber does is just bounce off of it. If you think the shop is going to try something different at first I doubt it, a press is gonna be like last resort. A good mechanic would just tell you striaght up how to do it yourself besides you should have a good plastic mallet as a tool anyways. Things like rounded or flat punches, hell one time I used a BMX bicycles 1 piece style crank cause it had the right bend one time.

 

[egmike]

I will pick up a plastic mallet and a torch and give it another try on the weekend

thanks for the help