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Vertex 2-Stroke Piston Kit - Stock Bore

Retail: $86.97 - $295.97
$72.99 - $243.99
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Product Description

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.
  • Circlips.
  • Competitive price!

Wiseco Needle Bearing:

The Wiseco Needle Bearing is a high quality replacement wrist pin bearing designed to withstand the harsh demands of racing. Wiseco built their needle bearing to meet or exceed O.E.M. specifications.

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.

  • Customer Reviews
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(29)
4.7 out of 5 stars
5 star   25
4 star   2
3 star 0
2 star   1
1 star   1
Deema00 Location: Napa, CA, USA
1-10 of 29
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Location: Binghamton, NY
Great piston

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!

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Verified Purchaser
Location: Napa, CA, USA
03 CR250 Top End Build

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.

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Location: Napa, CA, USA
03 CR250 Top End

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.

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Verified Purchaser
Location: Phoenix, AZ, USA
Great Purchase

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!

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Verified Purchaser
Location: Daytona Beach, Fl.
Vertex piton kit

Very good quality part. Installation was a breeze. Easiest 2 stroke top end I ever did. And Fast shipping too.

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Verified Purchaser
Vertex piston in 99 YZ250

I ran a Wiseco last time and tried Vertex this go round, installation was simple and easy...pin bearing was same as factory so good there. Ran about 5 hours so far and power is excellent, actually feels like improved throttle response over the Wiseco.

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Verified Purchaser
Good product and overnight delivery awesome!

Fairly easy to install. Only issue I had was with retaining clips. KTM makes them really hard to get out and back in without scoring the piston so be careful. Save the old one just in case you shoot one across the garage and lose it like I did.

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Verified Purchaser
So Far so good

The kit worked excellent so far. Have about 25 hours on it and compression still feels great!

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Top 500 Contributor Verified Purchaser
Location: Valencia, Santa Clarita, CA, USA
Vertex Piston Kit

I have been using Vertex pistons for years now and have been impressed with the longevity and durability. The work great in my KTM 250SX and would recommend them to any KTM owner.

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Verified Purchaser
Location: Phoenix, AZ, USA
Item isn't what is shown or what you will read

i received my piston kit today in the mail, I was ready to install my new piston kit upon opening package I noticed that it only had a single piston ring not a dbl piston ring as it clearly shows and it clearly states when you read the product description and it states it comes with piston piston "rings" witch means more then 1 piston ring !!! Needless to say I was very disappointed..

1-10 of 29
Total Questions (7)
Questions with answers:
  7
Questions without answers:
0
MXMTBB17 Location: Summerfield, NC, USA
Fanis Location: ATH, GR
1-7 of 7
Mitch 1 month 18 days ago Location: Yuma, AZ, USA
What is the right piston for a 2003 CR125 bored to a 134?
I believe it's just a 0.080 over 125, correct?
MotoSport Staff Expert
1 month 18 days ago Location: Portland, OR, USA
Yes, you are correct that the .080" oversized piston for the CR125R is the 134cc piston. Unfortunately, I do not show that we have that size piston available in a Piston Kit, but we do offer the Wiseco Wiseco Pro-Lite 2-Stroke Piston - .080" Oversize (with rings, wrist pin & circlips included) then you would just need to order the gaskets and wrist pin bearing separately. Here is a link to the .080 piston you are looking for: http://www.motosport.com/dirtbike/Wiseco-ProLite-2Stroke-Piston-080-Oversize
MXMTBB17 2 months ago Location: Summerfield, NC, USA
Completeness of gasket kit?
I am rebuilding my 2006 RM 250 RC Edition. While replacing the piston I am also fully cleaning the power valve and replacing the the reed with a Boyesen Power Reed kit. Can you tell me exactly which gaskets are included with the top end kit?
Expert MotoSport Staff
1 month 28 days ago Location: Portland, OR, USA
The Cometic Top End Gasket kit for your 2006 Suzuki RM250 would include the following; Outer Head O-Ring, Inner Head O-Ring, Base Gasket, Exhaust Gasket, (2) Expansion Chamber O-Rings, Right Side Power Valve Gasket, Left Side Power Valve Gasket, Front Power Valve Gasket, and the Power Valve Spring Gasket. Any other gaskets would need to be purchased separately.
Fanis 3 months 1 day ago Location: ATH, GR
Piston to cylinder clearance?
How much piston to cylinder clearance is suggested by Vertex? It should be written in the instructions paper and i need this information in order to decide if i can fit the standard piston. Thank you.
MotoSport Staff Expert
2 months 16 days ago Location: Portland, OR, USA
I contacted Vertex directly on this and they said you will want 3 to 5 thousandths piston to cylinder wall clearance on 2 stroke models.
Riedemann49 Over 6 months ago
What size is this piston it does not stay?
MotoSport Staff
Over 6 months ago Location: Portland, OR, USA
The piston size will vary depending what bike is profiled. This will be a stock bore piston and would match the stock bore of whatever bike is profiled when ordering. These pistons are model specific so please make sure to have your bike profiled correctly when ordering.
Austin Over 10 months ago Location: Big Lake, MN, USA
Does this kit include the o-rings for the cylinder and cylinder head mating surface?
Top 1000 Contributor Top 500 Contributor
Over 10 months ago
Yes if you buy the whole piston kit it will comes with all top end gaskets and o rings
MotoSport Staff
Over 10 months ago Location: Portland, OR, USA
Yes this kit will include all the gaskets and o-rings from the base gasket and up, to rebuild the top end.
Over 10 months ago Location: Boston, MA, USA
yes this kit does include the o-rings both inside and outside
Over 10 months ago Location: Phoenix, AZ, USA
Yes, this kit includes all gaskets and o-rings needed for a complete top end rebuild.
Over 8 months ago Location: Nassau, NY 12123, USA
Yes the kit comes complete with all top end gaskets.
Top 1000 Contributor
LaRider20 1 year 1 month ago Location: Louisiana, USA
Does this piston really have two rings like in the picture?
MotoSport Staff
1 year 1 month ago Location: Portland, OR, USA
This will depend on the application. Some 2-stroke piston kits will come with a dual ring.
Over 11 months ago Location: Phoenix, AZ, USA
If you have a 250 2T then yes your piston will have two rings but if you have a 125 2T then no it will only have a single ring included
Over 10 months ago Location: Virginia Beach, VA, USA
I am not sure about all the models but I the RM 85 only has one ring.
Over 10 months ago Location: Boston, MA, USA
This piston, like many other 2-stroke pistons has only one ring. This is especially common for small 2-stroke engines, because it helps to avoid lubrication issues.
Top 1000 Contributor Top 500 Contributor
Over 10 months ago
It depends on what bike your riding I just got a kit for my yz 250 and it had 2 usually 125's have 1 and 250's have 2 wiseco and vertex make a single ring 250 piston though
Over 10 months ago Location: Big Piney, WY 83113, USA
Depends on the bike
Over 8 months ago Location: Nassau, NY 12123, USA
The YZ 250 piston did I got.
aaronabiles71 1 year 1 month ago Location: canton GA
How do I check cylinder bore ?should I bore?
Doing top end
MotoSport Staff
1 year 1 month ago Location: Portland, OR, USA
You will need to get an accurate measurement of the piston with a micrometer or calipers. This is important to determine what size you need to replace it with. Checking the condition of the cylinder will also determine whether or not you need to have it machined (this could change the piston size as well).
Over 11 months ago Location: Phoenix, AZ, USA
To check your cylinder bore use a bore gauge to determine the diameter around the cylinder. And boring out your bike is a personal preferance
Over 10 months ago Location: Boston, MA, USA
to check the cylinder bore you should use a micrometer. you should take multiple measurements and use the average. One way to check if you "need" to Bore/Hone your cylinder is to take your finger nail and run it arount the inside of rour top end. If you can feel bumps or the inside is not smooth you deffinatly need to hone/bore, or replate your cylinder. I would recomend that you always hone a cyilinder if the top end blows up. it will give you better compression and there fore better preformance. Also if you do this be sure you don't use a ball hone, it will damage your ports.
Top 500 Contributor Top 1000 Contributor
Over 10 months ago
The best way would be to take it to your local shop and have them do it u can do it with dial calipers but its not an accurate measurement and they may not charge you anything. As far as boring goes you might have a coated cylinder if that's the case u need to get it replated if its messed up and just have it plated stock bore
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