76 DT400. Trying to remove bottom piston ring but it is stuck solid on the piston. Doesn't move at all and nothing to grab on to. Top ring was similar but was loose on one end so I could slowly work it loose with hand pressure. Tried using my heat gun on low with wd40 but didn't know if I could damage the piston at all with too much heat. I assume the bottom ring should spring outward like the top ring does? 

Curious if top ring was L-shaped?

And yes, the answer to the top ring being L-shaped or not is relevant to the stuck bottom ring. 

 Just give it a tap in the end with a small screwdriver & might pop free to then work around. Or get serious as my pics will show. Saved them & ran like a champ. yamaha-enduros.com/index.php/forums/1968...0-s-at-a-guess#42751 Just give it a tap in the end with a small screwdriver & might pop free to then work around. Or get serious as my pics will show. Saved them & ran like a champ. yamaha-enduros.com/index.php/forums/1968...0-s-at-a-guess#42751

Back to the main story. Bit unusual for the second ring to stick like that & i thinking it might be a taper top keystone ring too so even less likely therefor wonder whats going on--what caused it. Maybe just carbon if high mileage but think they have an expander behind too.

RT325...  I'm wondering if someone jammed incorrect rings into the grooves.  Looks way too clean to be stuck from anything else.  That's why I asked about the top ring.

Yes the top ring is an L ring. I believe this is an original piston. Has a 1975 date on top. Engine was sitting for a very long time. Still lots of cross hatching visable inside. Mostly wear free but a little cruddy in there.

I probably would put on a pair of work gloves and get an X-Acto knife and see if I can cut around the perimeter of the ring carefully without scratching anything up that needs to be repaired later and spray a little bit of the blaster to loosen it up. Then I would take a ring gap measurement.

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Yes going to be iteresting when you get it out.

I would use a small pick or screwdriver at the gap and gently tap with hammer to spread like RT325 said.