On Sun, 27 Jun 2010 13:57:10 -0700 (PDT), Roy Quijano
wrote:

On Jun 27, 4:26*pm, Oren wrote:
On Sun, 27 Jun 2010 14:27:06 +0000 (UTC), Chief Two Eagles

wrote:
It's not worth taking in for repair as the labour would cost more then
the thing is worth.

Hone the cylinder. Replace piston and rings to match the new diameter.
Might need to re-seat the valves using lap compound. Have to admit I've
never had a really small 4 stroke apart but it should follow the agenda
of larger 4 strokes.

A little extreme I think. It may need just a fuel / air mixture
adjustment.

That is not extreme at all, well maybe you don't have to hone the cyl.
much but you def. Have to clear it smooth an the piston and rings need
be checked n replced according.

The OP did not mention changing the spark plug. Just reading the plug
can tell you about serious internal damage*. If the plug is fouling he
my very well have unburned gases coming from the carb/exhaust....

I would change / gap a new plug and try again. I would not be going
into the engine without some minor checks or adjustments (less
costly). YMMV

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