Used this in a 2011 kx85. It's been through 2 woods series races and is holding up just fine. Every bit as good as any other brands I've used.
Vertex 2-Stroke Piston Kit - Stock Bore
- 42 Reviews
- 31 Questions
The MotoSport.com Vertex 2-Stroke Piston Kit - Stock Bore includes one of each of the following components with the following attributes:
Vertex 2-Stroke Piston Kit:
Important Note: This piston is for a stock sized bore. Please measure your cylinder to check clearance before ordering.
As the O.E. supplier of two-stroke pistons to KTM, Vertex Pistons has an outstanding reputation for quality and performance. Each gravity cast piston is created with only premium aluminum alloys utilizing an 12 - 21% silicon content.
The silicon content in Vertex pistons is crucial to the quality of the piston. Silicon is critical in decreasing thermal expansion which, when an engine reaches normal operating temperatures, can change the geometry of the piston. Controlling this expansion means that a Vertex piston can be run at tighter tolerances for more power, less noise and a longer lifespan of the piston. Plus, the silicon content decreases wear on the piston skirt which also aids in the life of the piston.
In addition to the silicon, each Vertex piston utilizes a unique Molybdenum Disulphide (MOS2) coating which aids in the break-in process and reduces overall wear.
Vertex Piston includes:
- Premium quality Vertex piston.
- Complete set of nitride coated or chrome-plated piston rings.
- Fully case-hardened wrist pin.
- Competitive price!
Hot Rods Needle Bearing:
- Case-hardened and silver coated, the bearings are just as tough and reliable as all Hot Rods parts.
- Wrist pin bearing is specially designed with a long shouldered bearing cage to withstand high RPM use.
- Can be used with Hot Rods connecting rods and O.E. or aftermarket pistons.
Cometic Top End Gasket Kit:
State-of-the-art gaskets is what Cometic has been doing since its inception in 1989. This comes from their dedication to constructing gaskets for the most demanding race circuits like AMA and NASCAR. Today's lightweight engines are producing more horsepower, higher cylinder pressure, clamp load and extreme temperatures. Cometic's commitment is to provide innovative, quality gaskets while maximizing your engine's power and performance.
Cometic meets the needs of each specific gasket by using materials to match. Even the basic top end gasket kit features different materials for each gasket. The head gasket is constructed from non-asbestos, flexible graphite that is laminated to a stainless steel core. The manifold and base gaskets are constructed from non-asbestos nitride rubber-bound fiber. Cometic also includes copper gaskets where needed.
Cometic designs and builds their gaskets in the U.S.A.
Note: Image is for reference only, actual Kit may vary based on contents and fitment.
Parts seems of good quality. I like that the needle bearing it comes with us hot rod. Haven't ridden with it yet so I can't speak on power or reliability. My only complaint is it didn't come with the copper crush washers for the head bolts that my YZ 250 has. I didn't notice untill reassembly. Had to order them separately. Would rather pay more for the kit and have them included. Other than that it went together great.
This gave me everything i needed to swap out the top end on my KTM. What a dream, no running back to the shop for a gasket, or needle bearing. I highly recommend this kit, and the Vertex pistons have lasted for me with no issues.
Ordered this kit for 2013 KTM 85 sx. Description says "standard bore'" but apparently, KTM produces engines with "A", "B", and "C" bores from the factory. These are just three different size pistons that vary by a fraction of a millimeter and are fit to each motor individually to help account for variance in machining and plating of the bores. The piston I received was a "B" unit and it turns out that our bike was fitted with a "C" piston from the factory. I wish that the item description had spelled this out so that I could have gotten the "c" piston instead, but there was no mention of this in Motosport's description. I installed the "b" unit and I'm sure it will be fine since I will replace it in about 20 hours anyway.
Shortly after installation of this piston and break in my engine seized. A large chunk of the top of the piston broke off wedging itself between the head and the remaining piston, destroying not only my new piston, but also my cylinder and head.
Researched rebuild days before part showed up. Made job easy.
Great replacement for stock.
Never have a problem with this top end in my sons yz-85
everything you need
This is a great rebuild kit. Very high quality parts. The only improvement that I think could be made is if Cometic decided to put a paper in their gasket kit that labeled each individual gasket and O-ring. Other than that, fantastic product. Just as good, if not better than Wiseco.
Restore the power in your bike byu using quality parts!
Got the piston kit for my cr 125 it had no compression.
After i replaced the piston and ring wow what a difference. Before i changed it i was able to start the bike with my hand. Those days are over .
Love these guys! The vertex piston fit perfectly and the cometic gaskets are working as advertised. In fact, the expansion chamber o-rings fit much tighter than OEM so no more oil spooge from exhaust! Thanks motosport!
I will buy again! Installed on a 97 cr 125 that had a dime size hole in the Piston marked clearly fits factory specifications. Gaskets that come with the kit are way better then the oem paper gasket
because this piston is not forged its cast which causes weak spots in the piston and after about 8 hours of run time always on a track with races the skirt of the piston blew off and ruined my cylinder and crank.
I decided to do a top end on my cr125 this winter and change it up from my usual Wiseco piston. Now that the snow is melting I can finally get back out and ride and this piston is great in my bike. Would definitely recommend this kit!
Super Stoked on the Vertex Top End Kit. The power is back! It came with everything needed for the rebuild. Installation was easy and a breeze. I recommend this set-up for any CR owner. Quality, Super Quick and Great service. From Motosport to my House to My Bike. couldnt be happier to be back riding.
Super stoked on the vertex top end kit, the power is back in my 2stroke. The kit came with everything needed to re-do the top end. Straight from Motosport to my house to my bike! Recommend this set-up to any CR owner. Quick, Convenient, and Quality. Everytime.
I have ordered numerous parts from Motosport for my son's dirt bike. It is easy to order, it always ships on time, and I have never had any issues with the quality of the parts I ordered. I recently ordered a piston kit for his dirt bike. It contained everything I needed to rebuild the top end of his bike. Thank you so much for your service!
Very good quality part. Installation was a breeze. Easiest 2 stroke top end I ever did. And Fast shipping too.
Also, feel free to give us a call at 888-676-8853 and we would be happy to help you out with your order.
Dirt Bike / ATV: 1-888-676-8853
Remember you want to maintain about a 0.05mm (0.002”) piston to cylinder clearance.
*The image is a generic image supplied by the manufacturer for reference only. It may not be displaying the exact part for your bike.