Ready-to-install, direct bolt-on cylinders require no re-plating and look virtually identical to the OE cylinders
Cylinder kits include matched Vertex pistons to ensure longevity, performance and reduced engine noise
Nickel silicon carbide-plated for long life
Kits come complete with gaskets, cylinder, piston, rings, pin and clips
Big bore cylinders do not require machine work (unless noted)
Product Note:
Specification
Details
Compression Ratio
11.7:1
Displacement
159cc
Size Over Standard
2 mm Larger than Stock
Vehicle Fitment
Fitment is guaranteed or your money back plus free return shipping.
Don’t waste time installing a product that doesn't fit. We worked hard ensuring that this product is an exact fit on the vehicles listed below.
Honda
CRF150R 2013-2024
CRF150R Expert 2012-2019
Customer Reviews
Big bore kit 2003 wr450f
By Randolph B. on
Verified Purchaser
Installed big bore kit on 2003 wr450f.
Fit as it should. Happy with the purchase.
Big bore power
By Mike on
Just what I need to get that much more grunt out of my bike. Awesome kit!
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Questions & Answers
What brand of piston comes with the kit?
By RPM955
Cylinder Works big bore cylinder kits come with Vertex pistons.
Will this fit on a stock 2002 yamaha 250 2 stroke
By Anon.
Yes, when choosing the kit to fit the 2002 YZ250 two-stroke, you would simply be installing the kit in place of the stock components. No machining or any other special parts would be needed.
Do the cylinder heads need to be bored to match the jugs?
By Frank
It is not necessary to have the head machined in order to use the big bore cylinder kit. Depending on what machine you are installing it on, you may need to machine the cases. Once you select your machine before adding to cart, it would mention if that is necessary.
I'm looking at getting this bore kit for my 2009 Kx250f what else should I also get new cams as well
By Tim
Cylinder Works Big Bore Kits are designed to work with OEM or any aftermarket cams that fit the OEM cylinder head. Just be sure to choose the correct cam for the kind of power you're looking for and you should be all set!
2007 crf150rb when using this big bore kit do I need to replace my cylinder head as well??
By Jeff
The CRF150RB's big bore cylinder kit works with the OEM cylinder head. There's no need to replace it. Though, since you've got everything torn down, you might as well have some head work done as well and take advantage of that extra displacement.
Big bore kit additional parts
By Anon.
I have a 2007 yz450f. What aother engine parts should I change to get the most out of the big bore kit? Thanks.
I would suggest looking at the Hot Rods Stage 2 Camshafts for your 2007 Yamaha YZ450F. When used in conjunction with the Cylinder Works Big Bore Cylinder Kit this will give you a larger boost in performance over the stock cam profiles. You can find those cams by simply searching our store for "Hot Rods Stage 2 Exhaust Camshaft" and "Hot Rods Stage 2 Intake Camshaft"
Can i change my cam to a stage three without having to change anything else or what should i do?
By nick
When you install big bore cylinder kit it's recommended to change your cams as well. Any time you change the displacement of the engine, you should match the valve diameter and cam lift to to the bigger set up if you want to get the most power out of the new set up.
Let us know what you'r working with and our team will be happy to help you find a complete kit with everything you need to get the most power from your ride.
Have a question? Please ask our experts and customers who own this product.
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