I've had this odyssey sitting in storage for years. The last time I rode, it died on me and just have not had a chance to fiddle with it. When I tried starting with rope pull, after a few pulls the Engine locked up. I took the head off to expose the piston and there was a chip of metal on the side of the piston ( picture shows this on left of piston). I lightly hammered piston down and metal piece came out. I can now pull the cord. I still have not gotten the Odyssey started, but one problem solved. My main question, as this is all new to me, is what caused my piston to look like this and is it ok? I am by no means an expert, any help would be appreciated.

That piston is definately not ok. You need to remove the cylinder next. Take your time and don't go hammering on things. Your owners manual will be handy right now. You should never have to hit your Engine with a hammer. It's gonna need a piston at the least. Hopefully that's all the damage. You definately came to the right place for help.

i really want to see the piston after it out
it looks really thrashed

Wow that's not good.

Thanks for the replies. This is going to be a weekend project. When I get piston removed I will post new pics. Oh, when I say I hammered the piston, I meant I used a hammer and piece of wood to dislodge the piston. I did not take much effort to knock down. What would cause the piston to look like this?

Piston is burned up from over heating probably caused by detonation if the whole Odyssey is stock and the jetting is stock over heating can also be caused by the jetting being too lean.

Minimum the Engine will need a piston and gasket kit, the cylinder honed but until its apart, inspected and the cylinder measured you wont know if the cylinder needs bored.

Plenty of Engine CSI's to read here http://www.pilotodyssey.com/PO/viewforum.php?f=26

A new piston looks something like this

Yeah, not at all what my piston looks like. I've been doing a bunch of reading of different posts, great information on this site. One thing I noticed when removing the top head, there was no gasket between what I assume is the bottom and top of Engine. Basically there was no gasket where I have taken a picture. Not sure why there was no gasket, I am not the original owner. Could this have caused all the buildup on the piston?

the gasket is thin metal sheets. looks like it is stuck to the cylinder down on the studs

Make sure you flush out the bottom end/case with 2 stroke mix,swish it around and tip out onto a CSI surface.
Wire brush your cyl/head stud threads,lots of rust there,if not you will have a detrimental affect on your torque settings/specs on reassembly.
When it's all rebuilt,do NOT start UNTIL you do a thorough Air Leak Test on complete Engine.
If not.....you will have a 2nd go at ANOTHER Engine rebuild! TILL ya LEARN like we ALL have done!
You need to determine WHY this all happened to start with.Otherwise your just another CONSTANT buggy Parts Shops buyer.
Air leaks are a major cause, due to faulty gaskets,vaccuum lines,carb boots,etc.
One step at a time,not 2.
Being Lazy is the worst thing now....will come back and bite ya in the A later!
http://www.youtube.com/watch?v=G3lJwyQ_2Qg" ."..

Ok, I just completed next step to expose rod. I took many pictures, if more are needed please let me know. Does anyone see any damage to rod. I know my piston looks horrible and the metal that jammed piston was a piece from the piston rings. Any advice on what to do next would be appreciated. Again, by no means am I an expert on Engine repair, but I do like to do things myself.

By the way, nitrosport_5, you are correct. I did have 3 gaskets.

I will get a gauge to find out if cylinder needs bored. A few more pics.

Is it me or does the skirts on the base of that jug look really really thin? See that? What size piston is in that thing?

I hope to get a micrometer in a day or so. Can someone recommend someone to do cylinder work for my 350. I live just north of Dallas, TX?

The skirts look fine to me. I can see why you thought they looked thin, the shadows tried to fool me as-well.

-Nick

It actually looks really thick. I would say that is a stock art piston and by the look of the base gasket that Engine has never been apart before. The base gaskets honda sold at the dealer had the dimples in them to stop oil migration.

Take a look at the sleave by the transfer ports you can see how thick it really is. The shadow is distorting the pic a bit. At first I thought the same thing

Bore reads 78.5mm

Any recommendations on where to get this bored. I've noticed Hoser does work for others. Hoser would you be interested in getting this working? I'm new to this board, so hopefully this is not inappropriate for me to ask.

that Engine most likely has never been apart. the 78.5 is a stock piston. If you don't want to waste a bore, you need to find someone that has a NOS .20 over piston they are willing to part with. The Wiseco will bore it out all the way to 80mm and waste quite a few bores in between.