Could have sworn someone asked this same question but cant find it in a search and I cant find a piston chart.Bought this Engine off ebay,its sposed to be a runner but its being tore down first by a buddy who knows just a little bit more than me.Its a 1985 200x Engine.How does the cylinder and piston look to yall? And I need to identify piston.He measured it and thinks that's the stock piston but i find that hard to believe.

I call that a pumper ( oil into the top end) motor (( Internal Combustion Engine ? )) (Engine) the gaps on the oil control ring should not line up.

I don't know what that means?

bump

The two top ring are your compression rings like in a two stroke and the third or bottom ring is you your oil control ring or sweeper ring. The sweeper is made up of three separate ring put together to form one.In the pic the top and bottom of the third ring end gaps line up and allow oil to push right to the top of the piston by allowing oil up to the second ring through that gap and then past the top ring through it's gap. When installing this ( trird,sweeper) ring the top and bottom should be 180 apart. The middle portion will keep the two thin rings end gaps in place as the assembly rotates around on the piston as one assembly or ring. This will sweep the cylinder wall of its soil as the piston move down past TDC (Top Dead Center) and keep it out of the top end or compression chamber. Then the two compresion rings can do there job correctly. The way there on there that Engine will always smoke and is evendent from the look at the piston and the Engine will always use or burn oil. Thus pumper motor (( Internal Combustion Engine ? ))( pour oil in the case and it pumps right out the exhaust), as the piston travles down the sweeper ring is allowing oil to to pushed right to the top of the Engine. As the piston move down there is pressure created in the crank case ( reverse swept volume) This pressure must be releaved some how. In comes the PCV valve (Positive Crankcase ventalator) This vents off the pressure to the intake air filter area or should. Every seen some one take it out and stick there finger over it as the Engine is runnig. The valve if used also creates vacume as the piston moves up and the valve closes via a mechinal spring in the valve. that's if one is equiped with it other wise the vent hose is routed into the filter area with out the one way valve. It's a quick check of the conditions of the rings. Bad ring low compression ( reverse swept volume). Lots of oil on the air fiter then bad rings allowing combustion pressure to push past the rings into the crank case and out the pcv valve. IN some mordern engines there is two compartments or dry sump like trx450 in your cse on the 200x its a single wet sump ( oil splasher, crank rotating in bath of oil) the crank and clutch/geas share the same oil.

In a four stroke the rings are installed according the manual. In a two stroke the rings have pin locks and in a four stoke the rotate around the piston. When installing they are pre set in a position according to hand on a clock or degree apart A good seal set up is 120 degree Y set up witht the third ring end gaps set 30 degree each side of the center Y and the lock ring ( spacer) of the third ring 30 degrees from one of the sweeper rings ( thin ones) end gap. No matter ehat follow the manual or the instructions that come with the piston. Always check the gaps and read allthe instruction that come with the piston. Each set up rings are a little differnt with each piston MFG.

that's a lot of info,thanks,but it doesnt answer my questions,lol.
Does this piston look reusable?
Does the cylinder need a bore?
How can I identify piston?
thanks

Use the manual as a guide to check the piston and cylinder wear, I would install all HONDA parts if you can still get them, everything piston rings gaskets.

well usually you guys can tell whether a piston or cylinder looks good or bad.To me both the cylinder and piston look good,but I don't know jack and i don't have proper measuring tools to see if this is in spec.If piston is good I need to identify it to find proper rings

I have no clue what the OEM pistons look like for that Engine.

Before I did anything I would research the Engine and find out what the cool popular reliable mods are for that Engine, its been to long I have forgot all the details I once read about, some of them engines were great for bumping the compression on some were not.

Some of them older small bore 4 strokes when you changed the cam and bumped the compression it made them unreliable and very hard to ride they were mostly good for WOT (Wide Open Throttle) narrow power ban all out racing at best.

You a member of the 3 wheeler board ? http://www.3wheelerworld.com/forum.php?

yeah im a member but I trusted the opinion on here more,Ill post there and see what happens