XR200 piston wrist pin stuck

[nedc]

After I broke the frame for the second time on my 83 XR200, I found a 2001 complete bike with stuck motor. Since i had completely rebuilt the 83 engine w/ Wiseco over sized piston, etc., I swapped that motor over to the 2001. I added XR250 front forks and shock and kept riding and enjoying the bike. Before I knew better and before rebuilding the motor, I had the decompression system not hooked up. Once I got smart and hooked it up, it was much easier to kick start (duh!). Well, I guess the damage was done because the other day, the kicker slipped and then it locked up. Now the bike won't even freewheel in neutral so I guess something inside the cases is jammed up.

I decided to take a look at the 2001 motor and see what's up with it. As you can see, looks like it was run low on oil and/or very hot and the piston tried to mate with the cylinder. Also, some of the skirt is missing!But the crank spins freely and there was not a lot of debris in the slinger- just oily, powdered aluminum swarf as you would expect. What i want to do is maybe put the top end from the 83 on the 2001 bottom end, but the wrist pin is locked to the rod and I have not been able to get it out. Not gonna bang on it, because I don't want to risk damaging the crank, but using a threaded rod and a big socket is not working either. I'm trying to avoid splitting the cases on either engine.

Included pics of the top end to show that there are no real obvious signs of oil starvation, which leads me to believe the bottom end is OK once I flush it out

Anyone have any ideas on how to get that wristpin out? Heat? dremel the piston off?

 

[S.O.A.N.Z]

Are you splitting the cases - just leave it on there if you are

 

[nedc]

No, I'm trying to avoid splitting the case.

[S.O.A.N.Z]

Angle grind it off

[nedc]

Yeah, I may have to 'get medieval' on it!

[Thickskull997]

Yeah, I may have to 'get medieval' on it!

You possibly could put some penetrating oil on it, soak it, leave it over night. If you are not wanting to save the wrist pin, use a punch and a mallet to hit it out. Be careful not to hurt your crank. If that doesn’t work, then grind it off.

[nedc]

Oh, I've hit it with all kinds of penetrants. I'm really afraid to bang on it for fear of hurting the crank. Maybe I will rig up some kind of fixture that holds the engine sideways and the piston solidly supported-then I can go crazy with the sledge hammer.

[S.O.A.N.Z]

[allrightythen]

A propane torch should expand the piston enough to at least give you a shot at removing the pin.

[N-8 Dawg]

Did you remove the circlips   

 

[nedc]

Yes, circlips removed. Beating on it with a mini sledge did not move it (on it's side w/ the piston supported so it could not move). Thinking I will take to the local machine shop and see if a hydraulic press can get it out.

[Doogee57]

  Ugh. Sounds like you've got a real problem there 'nedc'. Is the pin stuck in the piston or the rod? If it's stuck in the rod then the small end of the rod will probably be trashed.

[nedc]

The piston will not rotate/move at all which is probably what locked it up and caused the skirt to break. So, definitely locked on the piston...maybe the rod too.