What 250sx piston to buy?

[brandonlowe2]

I need to know what piston to buy for an ‘85 250sx. I am going up 1 size from standard bore (need at least 1mm larger) and all I can find is no name brand stuff on eBay and I am worried about the quality. I don’t see that wiseco has one....

I am hoping I am just missing something or is is the same piston as another machine .... What do I need?


Sent from my iPhone using Tapatalk

[125Mmadness]

There is a nos rocky 2mm kit on ebay right now for $75. Just search "atc250sx rocky piston" I would post a link but don't know how on a phone.

[fabiodriven]

Nothing beats OEM in my opinion, assuming it's still available.

[Scootertrash]

ProX is a product of Wiseco, but it doesn't look like they make a piston for the 4 stroke 250 either...........:wondering

Do you really need to go one size over? If you could get by with a hone and re-ring factory rings appear to still be available.

ETA: It appears that Shindy makes a piston for the 85 250ES. Honda part numbers are the same for both.

I've never used a Shindy piston, but their carb kits are good to go. Their stuff is made in Japan as opposed to China.

http://www.shindypro.com/about.html

One on Egay:

https://www.ebay.com/itm/Honda-SHINDY-Piston-Kit/162622954176?epid=630757979&hash=item25dd155ac0:g:5x8AAOSwZtlaIUHb&vxp=mtr

Thread from none other than 3WW:

http://www.3wheelerworld.com/showthread.php/126253-Who-will-admit-to-using-a-Shindy-piston-and-whats-your-experience-with-them

[Dirtcrasher]

If that Rocky is like the one I bought, it's been in my 86 250SX since 2000. I beat the snot outta that thing for years around my area and the track and the local riding areas.

I rode it so much, so hard, and treated it poorly in terms of riding it. I rode it like I stole it and bent 2 1986 complete rear diff/hubs/axle assemblies from jumping it, which they aren't made for....

It was a Rocky 2mm over, so I'm assuming that one you saw was also 11:1 compression.

Then I added a cam, Supertrapp and a 350X carb; They seemed to compliment each other and the 350X carb ends any cold starting issues if you had any...

[brandonlowe2]

Ok I will check that one out.... and unfortunately I have to go up a size. The previous owner apparently put a new stock piston in the same same with no work to it and ran cheap gas.... the cylinder is beat to crap. Rusted, pitted, and really rough. My bore guy says a minimum of 1mm will take care of it.

I will try that rocky one and see how that goes. It’s gotta be better than what I have




Sent from my iPhone using Tapatalk

[fabiodriven]

They make oversize OEM pistons.