Confused

Hey Dave thanks. Should be there any day. 👍🏼

Hey buddy just checking to see if you’ve received my check yet. Thanks for the update 👍🏼. Lew

Hey Enduronut have you had a chance to see if you might have the 2nd over piston I’m looking for ? Or just a good number would be great. Thinking I should buy a parts manual from the 70s if I can find one just to get the proper part numbers. Thank you so much for all your help. I did send you a message yesterday. Did you get it ? 👍🏼

Hey Eduronut. Wow thank you so much. I’m 64 and retired. I bring old bikes back to life because I used to ride them as a kid. When the pistons and rings that showed up I just scratched my head. Thank you for identifying them for me. So I took my cylinder and piston to a boring machine shop. He’s my age and had some really cool vintage stuff to. Anyway he looked at my piston and cylinder and took measurements. He said he can bore it if I get a 2 nd over piston. I trust him. He’s been there for ever and like I said has some really cool stuff. So I’m looking for a second .50 over piston kit. Or if you still do boring I can send you what I have and see what you think? Maybe you have the parts I need ? If I could purchase from you great. Either way the Lord put the right person in my path. Thank you again. I was starting to think it was me. 👍🏼

Welcome! Feel free to post pictures of your bike (if you want). If you do not want the incorrect pistons, & want to sell them, I might be interested in buying them. If so, you can use the members chat box and send me a private message.

Thanks

Welcome to our site . . . glad you found us . . . and yes, we can help

I don't know for sure why or how you ended up with the wrong pistons, but there's a Latin phrase ... "caveat emptor" (Let the buyer be aware). Unfortunately, there's no saying "Let the sellers be aware"

Over the years, there have been so many parts manual revisions made, and so many superseded parts added (and subtracted), that you have to be an experienced expert to sort things out correctly . . . not to mention the people making the revisions likely know nothing about the bikes or manuals they're trying to update. It's a real mess! Bottom line . . . It's probably not you.

So, 1st I'll identify what you've bought

the 285-11636 piston is a second oversize for a 1970/71 DT1MX (250cc model)

The other one (251-11636), is a second oversize for a 1969-1971 CT1 Enduro (175cc model)

Question: How did you determine that you need a 2nd oversize for your AT1? If it's toast as you say, it may need to be bored up to the next (or even two oversize) to make it right again. I'm only asking, because I don't want to see you rebuild your motor in vain . . . there's only one correct way to do it, and I don't know what you do or don't know about two stroke top ends. I'm just trying to help you avoid making costly mistakes moving forward.

I use to run a cylinder boring service, and still have all the AT1 piston sets in stock, but want to make sure you get the right one. Have you had the bore measured by an experienced machinist yet?

I