How to ID wiseco piston

[Atc GuY]

Hey got the 200x apart and it looks to have been blown up at on time But before the head gasket blew it was getting crazy compression. My question is how to ID if it is a wiseco piston? Right now the piston is a .020 over and looks like the rod is new along with a cam and chain. ( New parts that were on it: flywheel, piston, rod, cam chain guides, cam, cam sprocket ) Could this be a higher compression piston besides the fact that is .020 over? The piston has a "bump" in the middle with slots cut in it for valve clearance. Also the piston has a "C" on it. Valves/seats also look new. Still has hone marks on cylinder. When running it pulled hard and made my foot black and blue to kick over. I ran it on regular gas with no problems. It was harder than a '83 350x to turn over. Any ideas?

[SWIGIN]

sounds like a 10.25 to 1.....pics?

[Erics350x]

Post a pic of it. Might be a 12:1

[Atc GuY]

[Erics350x]

Its not a 12:1, more pics of the sides and under and we'll be able to tell

[oscarmayer]

there's machining marks in the sides so i woudl tend to lean more towards it's a wesico.

[Atc GuY]

Ok, I'll get pics, but it says 4156 on the left had side (from front of engine) and a W on the right

[Atc GuY]

[Atc GuY]

http://www.wiseco.com/Catalogs/Powersports/HondaATV.pdf
2nd page under 200x

[Erics350x]

Answered your own question. 10.25:1

[Atc GuY]

10.25:1 plus .020 over
Looks like I did get a good deal

[SWIGIN]

Post a pic of it. Might be a 12:1

he said it ran fine on pump gas....that was the dead give away

i never seen a 200x run 12-1 on pump gas and run fine

[oscarmayer]

so it just blew a HG?
if that's the case, i bet he didn't tune it right as it detonated, or the timing was off (not chain but actual inside the cdi area) and it detonated that way. could have ran 87 when he shoulda ran 91+ as well. that running wot could detonate as well.

[Atc GuY]

When I tore it apart everything was torqued wrong. Someone used a cheap gasket maker all over the inside of the head. The head gasket was re-used and was in really bad shape to begin with. Oh well, it will be put together with brand new gaskets so I shouldn't have any problems. It was tuned pretty lean but that was fixed before I rode it. The head gasket was blown on the cam chain side and the kick starter side. But it ran real good before that so it has to run better when I put it back together!