Anyone using Namura top-end kits?

[rpt50]

Amazon has complete Namura top-end kits for yz 125s for $89.  I normally run weisco in everything, but that is a significant savings!  Anyone have direct experience with these kits?

[Rocket416]

I've never used Namura top end kit but I did just replace my YZ125 top end for $106 using all OEM parts off of e-bay. Piston, ring, bearing, and all associated gaskets. Ordered from NCY Yamaha.

Edited April 16, 2014 by Rocket416

[nholden98]

There is a complete OEM top end kit on eBay right now for 05-13 yz125's for $87 I believe

[Alan48]

Namura is EVIL,,,that's the rumor anyway.

[sruiz67]

Namura is made in japan. I used vertex, wiseco, and namura, in my Yamaha blaster. I and everyone I knew was rough on that machine. All 3 pistons were great and one didn't out perform one of the others. Wiseco is a forged piston meaning it is machined from a block of aluminum. Namura and vertex are cast pistons. They are poured into a casting to be made. Some say the cast pistons can shatter over time and fall into the bottom end and cause damage. Regardless of how a piston is made it could in theory do that. I've never had one do that to me. If you want to save some cash get namura. On these forums a lot of guys are very brand specific and kinda like "who cares about money" and they would rather pay more for something if they think it is better. Personal experience I have used them all and no gain or loss with any of them.

[crfcryzyzfltz]

Personally, I have never used Namura simply because of all the bad stuff I heard about them. Do some hard ebay searching and you could find a great top end kit that's either OEM or something with a better reputation (my preference is Wossner) at the same price. Even if its a few dollars over, I would spend the extra $$ for piece of mind. That's my opinion.

[MattFisher]

I had a 1/4" section of Namura circlip break off due to a fluke metallurgy issue and imbed itself in the top/side of the piston of my son's RM85.  Took out the cylinder at the same time, of course.  As a bonus, their customer service sucked too.

 

You could send me a Namura piston for free, I wouldn't run it.  Re-plating the cylinder was not cheap and it could have taken out the bottom end too....

[shrubitup]

used a few of them. no issues IF recreationally riding trails. However, I've heard racing applications and seen deep sand at dunes smoke a new Namura piston. Compared to OEM you're not saving much (NCY Yamaha eBay store).

Edited April 17, 2014 by shrubitup

[rpt50]

Thanks guys.  I guess I'll just play it safe and go with weisco...

[zotis777]

Forged portions don't shatter, they'd rather bend, it would bang itself to a point the bike won't even start before it shattered. so in theory it can't. Personally, id use wossner, wiseco, or OEM. Im sure others are fine, but with them is luck of the draw. Currently Im using a wiseco and its fine.

[sruiz67]

If you order the wiseco piston you get a sick felt baggy it comes in. Pretty sweet.

[Tony211]

I've seen guys destroy some Namura pistons. I've personally used a lot of Wiseco pistons in my two strokes and always had good luck.

Vertex is also good, and have used Pro X.

Can't go wrong with OEM either, but lots of people have their own preference.

[NateInRoundRockTX]

I'm going to vote OEM.

[BDubb106]

I've used 2 Namura pistons in my Yz250. Will never use one again. The first I ran for 32 hours and it looked great when it came out. The 2nd I ran for 19 hours and when I pulled it out it had several hairline fractures. The thing was a ticking time bomb. Quality control is not the greatest from my experience. It's just not worth skimping to save the extra $20 for top of the line. 

[JBFL]

1st piston installed at .0018 I pulled at 22 hours it looked fine, bore is now .0021 and 2nd piston has about 11 hours on it. I'll get a better look at it this weekend, gotta pull the motor for transmission issue (again).

[shrubitup]

used a few of them. no issues IF recreationally riding trails. However, I've heard racing applications and seen deep sand at dunes smoke a new Namura piston. Compared to OEM you're not saving much (NCY Yamaha eBay store).

Correction, Namura piston at dunes was fine. Yfz450 dropped a valve - not Namura fault. The stories I heard were third hand so never actually witnessed/verified that Namura blew up. I ran four in my cr250. No problems. I would still buy oem for racing tho.

[Thewayshegoes]

I run them in my trail/play bike (96cr250)...replaced both and 40 hours. As stated above i wouldn't use them for racing

[yamahayz125rider]

I used namura about 4 times they arent bad. As long as your cylinder us in good shape and spec you will be fine. Give en a shot you have nothing to loose

[yzdude250f]

I have one in my yz250, wasn't bad for the price but not sure if I'll use one again, no complaints but I'd rather use oem or a forged