Just in answer to Robchap's second question:
If there's any scoring on any 2 stroke machine it must be repaired as the engine may never run right again and could continually give you problems. If there is scoring on your machine, then it is definitely possible to repair it. It just depends on how bad the scoring is. If you remove the crank pin and slide the piston and Conrod out of the cylinder, this is the best way to see the real damage to the bore. If there is deep grooves in the cylinder you will need a rebore and need to fit oversized pistons and rings, or find a second hand one. But if there is only light scratches and most of the scoring is concentrated on the piston skirt, then a quick hone and new piston assembly can be installed. Only If cylinder is in good condition.
On the other hand you may only have a stuck piston ring, as this is common on a two stroke machine. If this is the case, remove piston assembly and inspect piston skirt and cylinder condition. If no scoring, then just replace rings and clean bore, lubricate and assemble.
Of course the correct way to do it, would be to measure rind end gap and cylinder wear, but for the home owner this is not usually necessary.
You can save yourself a lot of money if you perform the repair yourself. As these engines can be easily rebuilt. Just remember to inspect other parts of the engine (bearing play, o rings) if you decide to strip it and rebuild.
I hope this information is useful to you. It may answer some questions for other members about rebuilding these engines.
