biglong350 said:
but does that sound like thats what happened?
Your description sounds exactly like the classic "engine sieze" situation.
For one of several reasons piston overheated, expanded due to the heat and then no longer fit in the bore of the cylinder. When this happens the piston jams into the cylinder and it locks up.
The reasons this could happen include:
) the lubrication between the piston and cylinder broke down. On a two stroke this could be from not using enough oil in the gas.
) The rings could have simply worn out and the hot gases slipping past the rings caused the piston skirts to over heat. This is why it is recommended to rebuild the top end on a preventative maintanence basis.
) The engine could have overheated. As the engine heats up the piston gets larger and the hole it is operating in gets smaller. There wasn't a lot of clearance to start with so when the engine overheats it can go to zero and then things go bad in a hurry. This will often happen if you are operating at WOT for an extended period. (were you holding it wide open on your ride home?)
) detonation: If your gas didn't have a high enough octane rating the resulting detonation will focus heat onto the piston and the "knock" can hammer away at it.
It is easy to get a combination of the above. Running cheap gas without enough oil in a worn out engine on a hot day and holding it at WOT for a few minutes is very likely to result in a blown engine.
There is a very good chance that all you need is a "top end" rebuild, which will be whatever repair to the cylinder (sleeve, bore, plate, etc.) and a new piston/rings. It is also a very good idea to change the wrist pin bearing. Throw in a set of gaskets and you should be good to go.
On the other hand, if the piston has a big hole in it or has pieces missing then there is a good chance that the missing material is down in the bottom end and you need to clean it out, which generally means splitting the case.
Rod