Cast Piston durability

[Evan Dodd]

I was looking at putting a Prox Piston in my kx 250 for my next rebuild. Have other things to get don't really want to buy a wiseco. How durable would it be in my bike, how long would it Last. I ride Michigan trails. Usually pretty tight averaging 30 mph. Also, ride Hatfield McCoy. Dont usually get on it hard besides the occasional drag race with friends. Would this Piston last a summer in my bike I will rebuild every summer anyway. Probably put 50-60 hours on it a summer maybe closer to 40.

[indy rider]

I'd choose the ProX over Wiseco  every time. 

[2strokenut]

1 hour ago, indy rider said:

I'd choose the ProX over Wiseco  every time. 

So in other words, your advice is suspect. Thanks

[2strokenut]

1 hour ago, Evan Dodd said:

I was looking at putting a Prox Piston in my kx 250 for my next rebuild. Have other things to get don't really want to buy a wiseco. How durable would it be in my bike, how long would it Last. I ride Michigan trails. Usually pretty tight averaging 30 mph. Also, ride Hatfield McCoy. Dont usually get on it hard besides the occasional drag race with friends. Would this Piston last a summer in my bike I will rebuild every summer anyway. Probably put 50-60 hours on it a summer maybe closer to 40.

What year is your KX250?

Why don't you want to buy a Wiseco? It's a far more durable piston and lighter as well.

[Motox367]

I use prox also . Use to always use stock but like the prox performance.  20 years of hard core mx racing only had one skirt break on a 250. Nothing wrong with weisco pistons tho the prolight2 and racers choice are nice

[Evan Dodd]

22 minutes ago, 2strokenut said:

What year is your KX250?

Why don't you want to buy a Wiseco? It's a far more durable piston and lighter as well.

I've got a lot of other things to buy. (Building it into a woods bike) and wanted to try saving as much money as possible which not sacraficing performance or durability. I've used them in my 89 Cr and they just seemed overpriced for what they are. Kx is a 99

Edited November 13, 2018 by Evan Dodd
Forgot something

[Motox367]

Ya cant beat price of prox piston kit. Ive used weisco with no problems in past but prefer prox in bike have now. 

[Evan Dodd]

2 minutes ago, Motox367 said:

Ya cant beat price of prox piston kit. Ive used weisco with no problems in past but prefer prox in bike have now. 

Ya that's what I was thinking. This is just my trail bike so I didn't think there was any need for a super expensive Piston. Would definitely run forged in my race bike.

[2strokenut]

ProX is nothing but repackaged OEM pistons. That's it. Looking at the cost of a Wiseco I see where you are coming from. The Wiseco can easily outlast the OEM 2 to 1 but if you're working with a budget there isn't anything wrong with OEM. Just make sure you replace it before it wears out and cracks.

 

 

[Evan Dodd]

2 minutes ago, 2strokenut said:

ProX is nothing but repackaged OEM pistons. That's it. Looking at the cost of a Wiseco I see where you are coming from. The Wiseco can easily outlast the OEM 2 to 1 but if you're working with a budget there isn't anything wrong with OEM. Just make sure you replace it before it wears out and cracks.

 

 

Thanks for the info

[Motox367]

11 minutes ago, Evan Dodd said:

Ya that's what I was thinking. This is just my trail bike so I didn't think there was any need for a super expensive Piston. Would definitely run forged in my race bike.

Beautiful prox piston 

Edited November 13, 2018 by Motox367

[turbo dan]

For a 250 the Wiseco is hard to beat.  I don't recommend their piston in a small bore application.  They run too much clearance and excessive taper.  They work but they are noisy as hell.  After a few of those I have gone back to cast in my 125s.

Pro-X used to be nothing but repackaged ART pistons.  I got one a couple years ago that was branded PRO-X.  Turned out to have approximately .020" clearance.  The part that pissed me off was Pro-X trying to tell me there was nothing wrong with the piston.  The Wiseco I took out was in better shape.  I ended up putting it back together with the old piston.  Perhaps the quality has improved but they definitely are not just repackaged OE anymore.  For the price of a genuine kawasaki top end at a place like partshark there's no good reason to go with a questionable aftermarket part.

[seer]

I thought i read here wiseco bought pro x. I just got one and the box says made in usa...not japan. 

[Motox367]

8 minutes ago, seer said:

I thought i read here wiseco bought pro x. I just got one and the box says made in usa...not japan. 

Piston says made in Japan tho on inside of skirt?

[seer]

7 minutes ago, Motox367 said:

Piston says made in Japan tho on inside of skirt?

No I dont think so . Sorry it was installed friday or id verify. 

[FaceDeAce]

What is the comparison cost of a Kawasaki piston? Just wondering why looking at aftermarket pistons over genuine oem kawasaki?

[turbo dan]

What application specifically?

[seer]

10 hours ago, FaceDeAce said:

What is the comparison cost of a Kawasaki piston? Just wondering why looking at aftermarket pistons over genuine oem kawasaki?

It varies. Who do you think makes OEM pistons? Not Kawasaki... They buy them from the piston manufacturer.  

Edited November 14, 2018 by seer

[FaceDeAce]

It varies. Who do you think makes OEM pistons? Not Kawasaki... They buy them from the piston manufacturer.  

Not likely. Kawasaki is not simply an assembly shop. Kawasaki Heavy Industries is a major world supplier of manufactured parts in multiple streams. Far beyond a bike builder. It is an interesting read and a broadening of knowledge about the scope of Kawi.

Back to the question. What is the price difference? Really, what is the driver for why are you looking at wannabe jobber aftermarket parts?

[2strokenut]

47 minutes ago, FaceDeAce said:

 

Not likely. Kawasaki is not simply an assembly shop. Kawasaki Heavy Industries is a major world supplier of manufactured parts in multiple streams. Far beyond a bike builder. It is an interesting read and a broadening of knowledge about the scope of Kawi.

Back to the question. What is the price difference? Really, what is the driver for why are you looking at wannabe jobber aftermarket parts?

 

Dude, it's well known that OEM japanese pistons are made by a company called ART. They are't made by Kawasaki. If the OP looks under the skirt he should see the letters art somewhere. Stop trying to sound like you know what you're talking about.

I didn't know a higher quality, forged piston was a wannabe jobber part. TIL