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How can I figure out what brand of piston I have?
Posted: October 29th, 2008, 4:45 pm
by Crow500
I don't have the compression that I should have in comparison to other 500's. I checked the cylinder and the walls look decent. I can't afford to do the whole piston right now, so I'm going to try a fresh set of rings. 90.00 is stamped/engraved into the top of the piston. I think the previous owner told me it was a Wiseco, but I'm not sure. How can I figure it out so I can get the right rings? Or is the bore size the only thing I need to worry about?
Posted: October 29th, 2008, 4:57 pm
by Uzi
Post pictures if you can.
I replied to this on the other site too. If you get a chance look a couple posts down in the "exhaust port too wide" thread there pictures of a few different types of pistons in there (pro-x and wiesco)
Posted: October 29th, 2008, 5:01 pm
by Crow500
You are quick

I think that I have a pic with the head off, maybe some from when the engine was split. How do I post a pic? I'll check the exhaust port post and see if I can recognize anything. I know that it is round.

Posted: October 29th, 2008, 5:09 pm
by iggys-amsoil
If you get a new set of rings and the end gap measures bigger than .020 then time is wasted. I was gona say money to but you can always take the rings back.
See if the piston intake skirt is cracked.
Posted: October 29th, 2008, 6:19 pm
by Uzi
Crow500 wrote:How do I post a pic?
Do you have a photobucket account or any other place on the web that you keep pictures? Just put the pictures there and then link them here with the "img" button thats up above by the subject line when you are posting.
It will look like this when you get done.
Also I stole this pic of an upside down piston from rob and marked it to show where the W is usually stamped if the piston is a Wiesco.

Posted: October 29th, 2008, 6:43 pm
by AlisoBob
If its cracked, its cast.
If its partially seized, its Wiseco.
....easy.
Posted: October 30th, 2008, 6:30 am
by britincali
Posted: October 30th, 2008, 11:00 am
by south central hoon
You will be wasting your time putting a set of rings in a bore that has not been honed. If you don't break the glaze in bore your new rings will not seat and you will be right where you started once you kick it over.
what is your compression? why did you tear it down?
Posted: October 31st, 2008, 6:40 pm
by Crow500
" what is your compression? why did you tear it down? "
It just doesn't seem to have to compression that it should. Kicks really easy in comparison to others. I know that I should do the whole top end to get the best performance, but I can't afford to do it all right now, but I still want to get out and ride. I'm trying to get some pics together right now.
Posted: October 31st, 2008, 7:00 pm
by Crow500
Here are the best pics I have for now.

Posted: October 31st, 2008, 7:36 pm
by 100hp honda
appears there a casting mark. looks like a proX i took out of a old motor, but someone said proX and OEM is the same thing but i dont know for sure

Posted: October 31st, 2008, 9:22 pm
by robertg
I thought OEM and ProX were made by ART? It should say on the inside of the piston.
Posted: October 31st, 2008, 10:28 pm
by Nodge
If you have it apart that far, spend a few extra bucks.
It will be WELL worth it in the long run.
Posted: November 7th, 2008, 7:23 pm
by Crow500
I finally got it all apart, it turned out to be a Vertex

I went to the shop by work to order some rings, but he can't get them. I think I ready somewhere that Vertex rings are interchangeable with OEM, but I'm not sure. I would prefer to use Vertex rings with the Vertex piston. Any idea where I can find them? It is a 90.00mm. When I do the whole top end, I'm going to go with a Wiseco. And the compression was only about 90. the cylinder looks good with no gouges and minor wear. I will get it honed first though.
Posted: November 7th, 2008, 7:27 pm
by Crow500
Another thing I'm wondering is, should I some how try to get the residual black sludge out of the exhaust, or when I get it tuned right will it eventually clean itself out?
Posted: November 9th, 2008, 12:39 pm
by Crow500
I finally found a part number on the Vertex site. It is 22447100, but I think that is for the piston. Hopefully I hear something from them tomorrow.
Posted: November 9th, 2008, 4:48 pm
by ISBB
usually they are marked on the inside of the piston.. I.E. my old prox has its name and part number cast into it on the inside of the skirt. Piston sizes are usually etched onto the dome of the piston. mine just said 1.0 heh
Posted: November 9th, 2008, 5:25 pm
by Crow500
I have the piston number, but I need the number for the rings or to find out if OEM rings can be used on it. It is a Vertex 2 ring design with 1183 on the inside of the skirt. I figure the guy that had the bike before me must have got a good deal on the Vertex since they stopped selling in the US. Of course he is also the one that welded the master link on destroying the o-rings and leading to a snapped chain.
Posted: November 9th, 2008, 6:08 pm
by ISBB
what size piston do you need? Look at vertex's online catalog and you can get the OEM part number that way and most bike shops can cross refrence that number with their distributors part numbers and get you what you need.
Posted: November 9th, 2008, 8:43 pm
by Crow500
I got the number for the piston that I have. My piston is still good, I just need the new rings. I'm going to check around again tomorrow and hopefully get a response from Vertex too.
Posted: November 9th, 2008, 10:50 pm
by ISBB
you need to see what size it is.. then get the rings that go with that size.. take for instance if you took the number off the pro-x piston i have.. If you call up pro-x and say i have piston such and such the guy is gonna go ya it belongs in a 500 but what SIZE is it.. mine was a 90mm piston thats what they wanted to know so i could get what i needed.
Posted: November 10th, 2008, 6:49 am
by Crow500
Crow500 wrote:I finally got it all apart, it turned out to be a Vertex. I went to the shop by work to order some rings, but he can't get them. I think I ready somewhere that Vertex rings are interchangeable with OEM, but I'm not sure. I would prefer to use Vertex rings with the Vertex piston. Any idea where I can find them? It is a 90.00mm. When I do the whole top end, I'm going to go with a Wiseco. And the compression was only about 90. the cylinder looks good with no gouges and minor wear. I will get it honed first though.
Yep, 90.00 is what I have too. I'm going to try to make some rings in the garage from old pop cans.
Posted: November 10th, 2008, 8:35 am
by dannygraves
dude, that piston is showing some nasty signs of blowby and possibly a worn bore. I would really bore it, the rings will be a waste of time...
it get the ring to work you need to hone it like south central said and if you do...well... you are already pushing it on a worn out bore.
sorry, but that thing isn't going to run right without a fresh bore.
Posted: November 10th, 2008, 8:36 am
by dannygraves
also, as far as cleaning, I won't put something back together without it looking spotless. you should clean out all the carbor and sludge you can.
Posted: November 10th, 2008, 12:00 pm
by ISBB
speaking of blowby.. do you remember where mine was coming from danny.. was it right around the ring end area? I remember them being a bit on the loose side like .023 or something like that was thinkin thats where my blowby was comin from..