250-500cc Pic of my WR250 Piston

This piston was used for 2 summers worth of riding, including 8 harescrambles, including one seizure while I was being schooled by the stock Mikuni carb. It still ran good.

Both sides of the piston look about the same.

I am amazed that this thing just kept going, and going, and going...

thrashed, how did the bore hold up?

It doesn't look too bad. Not perfect, but it will still work.

ouch. gots an air leak or shes lean in the middle/middle-top. make sure there is ZERO alloy/high spots in the bore or itll stick again. there's a liquid product for removing alluminum from bores but i forgot what it's called, sorry.

I am going to try a Pro X piston this time. The Wiseco served me well, but I wonder if the ProX will swell a bit more consistantly... ?

This bike was ran upside down, in the snow, under water, wide open for way too long while racing because I was too tired to shift, dead engine starts without much warm up, in 95 + F temps, way past its service hours, etc, etc, etc. During this same time, my buddies yz250 went thru 2 top ends while taking similar abuse.

Sounds reliable for the abuse it´s been through then=)! Do you know how many hours you got on it?

.

Yes, very reliable! I have no idea how many hours are on this piston. It was in the bike when I bought it, then I seized the motor, then broke it free and rode/raced for 2 years afterwards.

haha! Ok, that´s fantastic! And the bore is fine?

Sweet story and you sound like a true 2t rider ;0 ) ... I rode my 02 CR250 6 years on the same top end ... I was waiting for it to loose power or start making a ringing sound or something and it just never indicated any issues ...

Then I found this site after the 6yrs of riding because I purchased a 4t ... Then i started reading U gotta do this and U gotta change this in X numbers of hours ... Hours? I was like why? U can spent UR money as U want, but you don't have to change the rings \ top end every 30 hrs as I have read out here sometimes ... These are very durable engines and will deliver over and over ... I've never cut it short on its oil mix either ....

Yes, they are good motors! When I bought my WR, I bought it for cheap and treated it like a disposable bike. The WR was only meant to get me through until I could buy a new 250F. I ended up liking the 2 stroke, and still haven't bought a 250f. I will get a 250F when I find the right deal, but the WR isn't going anywhere.

When are you getting your CR250 back?

Disposable or not, those engines are very good ...

The 02 CR250 is sitting in Everett, WA waiting for the title to get changed over to my name so that can begin the process of importing it over here to the Philippines ... I purchased a 4t (08 TXC250) for riding here as I knew I'd be doing alot of street miles ... The 4ts are easy to ride, fast or slow and it is good bike, fast or slow, but I need a 2t .. a bad a$$ 250 2T ... A 250 Husqvarna 2T

There are good deals on the 4ts out there ... I'd say get a TXC because it has the hopped up engine with a trails suspension and 6-speed tranny ... Then decide if you want EFI or not and that pretty much sets the yr model to purchase ...

The TXC has close to 400 hrs on it ( 9600 KMs) and doing well .... this sort of breaks the ?100 hr limit(?) that is promoted for top end work here also ... I have the rings and will be doing this exchange in the near future ...

I think that we wll should have atleast one 2 stroke, and one 4 stroke.

Enjoy the hit of the CR250 when it returns.

Hi. Sorry for crashing your thread, but I have a piston-related question.

I just bought a 04- WR250. It has 12000km on the clocks. Piston has never been replaced. Previous owner claimed he was driving it quite nice, and that the bike has had a good life with frequent oil changes and air filter changes (cleaning/replaceing). The bike runs nice and strong. No particular noises.

Anyway I figured I might go ahead and do a piston change today, just for peace of mind. Then it hit me:

At work I have this nice litte camera that you can stick down the sparkplug hole to inspect the cylinder walls. Could it be an idea to do a visual inspection and perhaps a compression test? If these test come out okay, maybe I could postpone the piston change.

(I will offcourse only be able to view the cylinder wall, and not the piston itself. )

Harald

Halo Harald, if you want to look before you tear it down, removing the pipe and reed valve would give a better view.

Good tip. Thanks. Will Do.

It is not a surprise that the motor would still be solid after that much time. I pulled my 06 WR250 down after two years and about 1500 miles expecting to swap out the piston/rings. Everything was in such great shape I ended up bolting it all back together and it is still running on the original top end. Gotta love amsoil. The piston still had the original coating and the ring was still well within specs as was the piston. Ring still had nice bevelled edges and wasn't sharp at all.

I'm finding out now that the OEM piston kit is ~250 $ ... I'll go this route once and plan on rings only forever afterwards ...

The ProX piston that I won on ebay is out of stock (it makes me so happy to find that out after waiting a couple weeks), so I went with another Wiseco. Hopefully now that the bike is mikuniless, this next Wiseco will have an easier life.