[KirkN]

I would imagine acetone would cut the varnish that is holding those rings in.


wonder about the piston expanding too quickly from the stuck throttle and the rings getting stuck from that? who knows....



So, now I have some additional food for thought: I was able to remove the 2nd ring and the oil control ring(s) last night, and it appears they were being held in place by grit. When I got them out, it was clear that a very fine grit was all in the ring grooves and was acting as a wedge, holding the rings stuck in place. I cleaned the rings and the grooves a bit, and they seemed to move freely again! The top ring is still resolutely stuck in place, though.

That got me thinking about the original cause of the sticking carb (which I hadn't really gone into at all) - yep, the whole inside of the carb throat, including the throttle slide and it's bore contained the same fine grit. It was clearly the cause of the throttle slide sticking.

Hmmm.... where did that come from? Back to the airbox - yep, the air filter foam was degenerated and had left a large gap at the bottom of it's contact area. And of course, on this bike, there's no airbox cover. The top of the airbox is wide open, and when the seat is installed, it doesn't really prevent the back tire from flinging mud/dirt up over the top of the battery and into the airbox. The inside bottom of the battery box and the airbox was filled with fine sand in all the corners.

So, I think the poor motor was sucking in sand and it jammed both the throttle slide and the piston rings. I also think it might have screwed up the intake valve sealing. And, I think that's what gives the piston sides that 'sandblasted' look, as opposed to the usual wear marks one sees.

So, always be sure to check your air filter! I think when this goes back together, I might remove the airbox-to-carb rubber tube and just install a 2-stage foam pod type filter.

And, I'm going to try to figure out a shield or deflector for under the seat to help keep the tire from just flinging mud right into the area.

Thoughts and comments?