2006 YZ250 Piston Selection

WileCyot
Profile picture for user WileCyot
Posts
458
Joined
9/23/2014
Location
Katy, TX, USA
WileCyot
Edited Date/Time 6/11/2015 3:06pm
Alright guys, time for a never ending debate. Piston selection for a YZ250...

Options are as follows:

OEM Yamaha Piston - ~$100
Wiseco 808M06640 Single Ring - ~$173
Wiseco 804M06640 Dual Ring - ~$136
Vertex Replica Piston Kit - ~$130
CP-Carillo - ~$200
Namura - ~$60
|
seth505
Profile picture for user seth505
Posts
10217
Joined
4/1/2008
Location
SD, CA, USA
seth505 6/8/2015 7:44am
6/8/2015 7:44am
I had an 09 and changed them every 30-40 hours and I always used Wiseco forged (2 ring) after the stocker and my bike ran great/cylinder looked great til I sold it 3-4 years later. That's all I can add.
ianhendry46
Profile picture for user ianhendry46
Posts
394
Joined
8/18/2011
Location
Murfreesboro, TN, USA
ianhendry46 6/8/2015 8:27am
6/8/2015 8:27am
Well you can't really go wrong with an OE piston. With that being said, what is the majority of riding you do? MX, Play riding, trail riding? The single ring piston is more for a full time racer, or someone that can change the rings or piston more often. The two ring piston, which is what I recommend
for the average weekend warrior, will still give a you a power increase but with a little longer intervals for swapping it out. Don't go with namura, and I think most people here will agree with me on that. the vertex isn't a bad piston kit by any means. And I just can't justify spending that much on a cp. I hope this helps. Throw some pictures up!
Jakes Dad
Profile picture for user Jakes Dad
Posts
1864
Joined
6/22/2009
Location
Brooksville, FL, USA
Jakes Dad 6/8/2015 10:24am
6/8/2015 10:24am
Been buying Vertex for around $85 on ebay. I did just buy a ProX for the same amount, moly coated looks same as Vertex. The Wiseco single ring comes with a recommended piston to wall clearance of .001. Probably wouldn't go with that piston unless I was sending off the cylinder to Millenium.
WileCyot
Profile picture for user WileCyot
Posts
458
Joined
9/23/2014
Location
Katy, TX, USA
WileCyot 6/8/2015 10:28am
6/8/2015 10:28am
Jakes Dad wrote:
Been buying Vertex for around $85 on ebay. I did just buy a ProX for the same amount, moly coated looks same as Vertex. The Wiseco...
Been buying Vertex for around $85 on ebay. I did just buy a ProX for the same amount, moly coated looks same as Vertex. The Wiseco single ring comes with a recommended piston to wall clearance of .001. Probably wouldn't go with that piston unless I was sending off the cylinder to Millenium.
I'm not liking the idea of replacing rings left and right so I'll probably avoid the single ring. The amount of performance 1 vs 2 would provide is absolutely negligible for me.

I'm also looking into a flywheel weight to give it a more tractor like momentum. I'm 6'-8" and I need the motor to have more flywheel effect.

The Shop

See All »
markit
Profile picture for user markit
Posts
2641
Joined
1/10/2013
Location
Bogalusa, LA, USA
markit 6/8/2015 11:11am
6/8/2015 11:11am
Pretty sure pro x is made by ART and the same as stock, know they use to be when I had my RD400. not sure if the Vertex is a reboxed ART.
mxracer239
Profile picture for user mxracer239
Posts
174
Joined
12/19/2009
Location
Delaware, AR, USA
mxracer239 6/8/2015 11:41am
6/8/2015 11:41am
I put a namura piston in our 2000 cr 125, has about 20hrs on it no problems yet
slipdog
Profile picture for user slipdog
Posts
10054
Joined
7/25/2009
Location
Nor Cal, CA, USA
slipdog 6/8/2015 12:32pm
6/8/2015 12:32pm
markit wrote:
Pretty sure pro x is made by ART and the same as stock, know they use to be when I had my RD400. not sure if...
Pretty sure pro x is made by ART and the same as stock, know they use to be when I had my RD400. not sure if the Vertex is a reboxed ART.
Pro X is definitely ART and pretty sure Vertex is their own manufacturing company.
keeptwostrokesalive 6/8/2015 2:15pm
6/8/2015 2:15pm
I've never had any issues with wiseco, matter of fact I have used them very often and love them. With that being said I am currently running an OEM piston only because I found a killer deal on ebay. I didn't notice any difference at all in power, and I can't say which one will last longer yet either as I only have about 6 hours on this piston. But I will say my wiseco I pulled out recently after about 30 hours still was in very good condition! So with that being said, go for what you can get the best deal onTongue
Cygnus
Profile picture for user Cygnus
Posts
14845
Joined
8/15/2006
Location
Hanover, CO, USA
Cygnus 6/8/2015 2:19pm
6/8/2015 2:19pm
The wiseco 2 ring is the way I'd go. Have ran them for a long time and never had a failure. The only thing is to remember to warm it up to operating temps before riding. Don't want to cold seize it.
BAMX
Profile picture for user BAMX
Posts
2905
Joined
1/22/2012
Location
Fallbrook, CA, USA
BAMX 6/8/2015 5:27pm
6/8/2015 5:27pm
I vote for OE or ProX.
BobPA
Profile picture for user BobPA
Posts
8340
Joined
10/31/2013
Location
USA
BobPA 6/8/2015 6:22pm
6/8/2015 6:22pm
Cygnus wrote:
The wiseco 2 ring is the way I'd go. Have ran them for a long time and never had a failure. The only thing is to...
The wiseco 2 ring is the way I'd go. Have ran them for a long time and never had a failure. The only thing is to remember to warm it up to operating temps before riding. Don't want to cold seize it.
This
WileCyot
Profile picture for user WileCyot
Posts
458
Joined
9/23/2014
Location
Katy, TX, USA
WileCyot 6/9/2015 10:08am
6/9/2015 10:08am
I think I'll be going wiseco 2-ring. Thanks guys.
mxrose3
Profile picture for user mxrose3
Posts
2379
Joined
8/17/2006
Location
Delmar, DE, USA
mxrose3 6/9/2015 11:16am
6/9/2015 11:16am Edited Date/Time 6/9/2015 11:17am
I've grenaded TWO Namura pistons in different bikes. One was in a YZ250 two stroke - the top edge of the piston broke off, and luckily shot out the exhaust port without doing any cylinder or head damage. I replaced it with an OEM piston... no problems.
Then I bought a Namura piston on ebay for my 10' YZ450. After only about 10 hours, it broke in half at the piston pin. I had to replace the cases, crank, cylinder, and two valves. You all can make your own judgement, but I've already made mine.
Matt Fisher 6/10/2015 2:44pm
6/10/2015 2:44pm
mxrose3 wrote:
I've grenaded TWO Namura pistons in different bikes. One was in a YZ250 two stroke - the top edge of the piston broke off, and luckily...
I've grenaded TWO Namura pistons in different bikes. One was in a YZ250 two stroke - the top edge of the piston broke off, and luckily shot out the exhaust port without doing any cylinder or head damage. I replaced it with an OEM piston... no problems.
Then I bought a Namura piston on ebay for my 10' YZ450. After only about 10 hours, it broke in half at the piston pin. I had to replace the cases, crank, cylinder, and two valves. You all can make your own judgement, but I've already made mine.
I'll second what mxrose3 was getting at- Namura sucks and I'll add- their customer service sucks too.
lumpy790
Profile picture for user lumpy790
Posts
11822
Joined
9/18/2007
Location
York, SC, USA
lumpy790 6/10/2015 4:19pm
6/10/2015 4:19pm
smoker or a F?

I would not hesitate on going stock on either but a F can get other benifits from an aftermarket.
cwtoyota
Profile picture for user cwtoyota
Posts
2418
Joined
3/11/2013
Location
Tacoma, WA, USA
cwtoyota 6/10/2015 11:06pm
6/10/2015 11:06pm
WileCyot wrote:
Alright guys, time for a never ending debate. Piston selection for a YZ250... Options are as follows: OEM Yamaha Piston - ~$100 Wiseco 808M06640 Single Ring...
Alright guys, time for a never ending debate. Piston selection for a YZ250...

Options are as follows:

OEM Yamaha Piston - ~$100
Wiseco 808M06640 Single Ring - ~$173
Wiseco 804M06640 Dual Ring - ~$136
Vertex Replica Piston Kit - ~$130
CP-Carillo - ~$200
Namura - ~$60
If you run an hour meter and do good, consistent maintenance on your bike, there is absolutely nothing wrong with the OEM or other cast pistons. If you like to let things go longer, the forged pistons will not crack around the intake port like the OEM.

I've been running the basic Wiseco 2-ring pistons in both of my YZ250s for several years. They hold up fine and I'm pretty good about teardowns and proper maintenance.

You won't go wrong with almost any brand of piston on a 250 unless you are a pro level rider and ride the bike mercilessly.
On a 125 I won't run a cast piston, they aren't as durable in a failure as the forged piston.

The Namura brand isn't something I have tried or plan to. Seems to be a cheap knock-off, but like I said, I haven't tried one.
WileCyot
Profile picture for user WileCyot
Posts
458
Joined
9/23/2014
Location
Katy, TX, USA
WileCyot 6/11/2015 3:06pm
6/11/2015 3:06pm
What about Wossner?

Post a reply to: 2006 YZ250 Piston Selection