Aftermarket 250sx piston

[mmiguy2103]

Ok guys I am looking for a new piston for my 87 250sx. I am looking for a oversized piston and ring set. I will then bore the cylinder to that piston. I just want to see what people recommend for a brand to go with? And where is a good place to source one. I am at the stock size now and don't mind what oversized is used.


Thanks in advance guys

[barnett468]

You are best off just going the next size up that will clean up the cylinder.

You should check your valves to see if they are leaking also. One way to do this is spray some brake or carb cleaner into one port at a time then lift the head up and see if it is wet around the valve. You can sometimes also open the jaws on a vice then set the head on top of the vice then spray the ports then use a flashlight if needed to look at the valves.

Also check the face of the rocker arms for wear. If there is a small depression/valley in the center of them, they are worn and might be bad enough to replace.
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[mmiguy2103]

You are best off just going the next size up that will clean up the cylinder.

You should check your valves to see if they are leaking also. One way to do this is spray some brake or carb cleaner into one port at a time then lift the head up and see if it is wet around the valve. You can sometimes also open the jaws on a vice then set the head on top of the vice then spray the ports then use a flashlight if needed to look at the valves.

Also check the face of the rocker arms for wear. If there is a small depression/valley in the center of them, they are worn and might be bad enough to replace.
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Yeah thanks, I am doing a 100% restoration. Everything is either new or fully restored to new, all new bottom end, all engine cases powder coated with a high temp flat black, all new bearings, new connecting rod, crank balanced, finally got the cases back together and ready to get the cylinder up and going, got new stock valves and valve guides that I was able to find out of a Honda dealer in Washington like 7 years ago. Camshaft in mint condition still.

So yeah I will def get oversized just want to know what brands people are going with?

[350for350]

I prefer to use Wiseco on all of my rebuilds.

[Scootertrash]

I use Wiseco all the time. Wiseco is a forged piston, Pro-X which is a division of Wiseco makes a cast piston

[barnett468]

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I would prefer an original which are still available, but I have used many Wiseco's.
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[mmiguy2103]

Ok so OEM is discontinued so I would love to go wiseco but I don't see the 87 250sx model on their site. Is the tax 250 fourtrax the same piston?

[barnett468]

Ok so OEM is discontinued so I would love to go wiseco but I don't see the 87 250sx model on their site. Is the tax 250 fourtrax the same piston?

You can still get an orig honda piston as I mentioned.

[mmiguy2103]

Checked 5 different sites looking for oversized Honda piston even called 2 dealers and they are all discontinued. If you can show me where they sell them still I will grab one. But I cant find one

[barnett468]

Checked 5 different sites looking for oversized Honda piston even called 2 dealers and they are all discontinued. If you can show me where they sell them still I will grab one. But I cant find one

I just looked and the first over piston I found has been sold. There is one second over piston on ebay and honda still has the rings.

https://www.ebay.com/itm/1985-87-Honda-ATC-250-50-Piston-Rings-Vintage-Offroad-13103-HAO-305-3-Wheeler/264250995601?hash=item3d86963391:g:tZ0AAOSwW~JcT4C e&frcectupt=true