Top end

[14D]

So I'm going to be doing a top end on my 125 pretty soon hopefully and wanted to know, why are pistons on ebay so cheap? example-

http://cgi.ebay.com/ebaymotors/Kawa...torcyclesQ5fPartsQ5fAccessories#ht_1077wt_797

average cost from RMATV- $105 not including shipping.

http://www.rockymountainatvmc.com/p...ebCatId=17&prodFamilyId=3784&allVehParts=true

Are they NOS or something?

 

[SRAD97750]

Yep. New Old Stock will sit on the shelves for 20 more years if they don't sell it on ebay. That's why they are cheap. -BIG DAN

 

[suzuki_dude]

i would buy a wiseco

 

[14D]

Yep. New Old Stock will sit on the shelves for 20 more years if they don't sell it on ebay. That's why they are cheap. -BIG DAN

ohh, thanks



Also, should I get a new wrist pin bearing? right now it's kind of a get one thing(I don't know how old the one is now so I'm gonna replace it for safety) but in future top ends will I need to buy a new one every top end(piston change)?

Also what brand gaskets do yall like to use? I want quality but price is also a factor.

 

[SRAD97750]

YES YES YES YES.
DO NOT CHANGE ATOP END WITHOUT A NEW PIN BEARING.

I lost a bike due to this. Blew it's top end when I bought it. Changed the piston, plated the cylinder, and everything. Started it up and the old pin bearing seized and totaled the motor... again. Never even got to ride that bike. All over a $13 dollar bearing.

OEM gaskets
-BIG DAN

 

[cleonard]

YES YES YES YES.
DO NOT CHANGE ATOP END WITHOUT A NEW PIN BEARING.

-BIG DAN

+1 one on that

 

[14D]

YES YES YES YES.
DO NOT CHANGE ATOP END WITHOUT A NEW PIN BEARING.

I lost a bike due to this. Blew it's top end when I bought it. Changed the piston, plated the cylinder, and everything. Started it up and the old pin bearing seized and totaled the motor... again. Never even got to ride that bike. All over a $13 dollar bearing.

OEM gaskets
-BIG DAN

Ok, will do, thanks

 

[Mihylo33]

The Wiseco's on that ebay link aren't that cheap.... just order from RM since the shipping will be cheaper and faster...
I agree, wristpin bearing with every piston.

 

[BleedMarshal]

With every top end you will want to change the psiton, ring(s), pin, clips, gaskets, oil, mix, etc. You will also want to do a specific break-in period as well for an hour or two. Also, never put an engine together dry. Make sure parts are wet (decent oil sheen) when you put the bike back together, and some manufacturers call for a specific mix as well during the break-in.

Hope that helps.