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The wait is almost over. This is exactly what the big bore community has been needing. Stop paying huge amounts of money for worn-out used cylinders that require extensive repair work, or shelling out a fortune for NOS units that still leave you stuck with factory stock performance.
Exclusive to Two-Strokes Only, this is the very first entirely new, direct-replacement stock bore cylinder of its kind to hit the CR500 market. We kept the proven characteristics of the original Honda design and strategically modernized the rest to unleash its true potential. No hacking, no case grinding, no headaches—just a massive performance leap and unquestionable reliability in a true bolt-on package.
Whether you are rebuilding a blown top end or looking for the ultimate big-bore upgrade, this cylinder delivers modernized airflow and rugged durability without the need for custom fabrication.
What's Included & Optional Upgrades
Included in the box:
(1) All-New CR500 Replacement Cylinder (89 mm Bore)
Optional Add-Ons (Select from the drop-down menu):
Piston Kit: Complete drop-in piston kit ready for installation.
Top End Gasket Set: Everything you need to seal up your fresh top end.
TSO Billet Cylinder Head: Maximize cooling and performance with our custom billet head.
TSO Billet Exhaust Flange: A heavy-duty, leak-free upgrade over the stock cast flange.
Key Features
Strategic Porting Evolution: We kept what actually worked from the original factory porting and made critical improvements where they were needed most. The result is an incredibly reliable, highly versatile cylinder that puts out more power than any hand-ported OEM unit on the market.
Improved Exhaust & Thermal Management: Built around an improved single bridged exhaust port, this design maximizes flow while offering superior piston and ring support. We also engineered improved cooling at the top of the exhaust port duct to relieve thermal stress on the bridge, actively preventing the cracking commonly seen in bridged all-aluminum cylinders like the CR250.
Rugged Construction: Cast from high-quality aluminum and finished with a low-friction Nikasil plated bore for unmatched heat dissipation, oil retention, and maximum longevity.
True Direct Bolt-On: Drops right onto your factory bottom end. Zero crazy case modifications, machining, or bike alterations are required. Bolt it down and ride.
Universal Compatibility: Build it your way. This unit is 100% compatible with all original (OEM) and aftermarket reeds, pipe flanges, cylinder heads, pistons, and top-end gaskets.
Technical Specifications
Feature
Specification
Fitment
1989–2001 Honda CR500
Bore Size
89.00mm
Material
All-Aluminum Cast
Bore Coating
Nikasil Plated
Porting Style
Optimized Factory-Plus
Exhaust Layout
Improved Single Bridged
Thermal Management
Upgraded Exhaust Duct Cooling
Modifications Required
None (Direct Bolt-On)
Compatibility
Accepts all OEM & Aftermarket Top-End Components, replaces Honda 12100-ML3-680
Bring your CR500 into the modern era. Add to cart to experience the ultimate upgrade for your 500 top end.
Compatibility
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Customer Reviews
Overall rating: 4.9 / 5 from 58 reviews.
Shipping was fast, the product is great!
When you could still buy the shift forks from Kawasaki they came out of spec :-(
These are in spec and far better quality than Kawi's forks.
They are in the bike and vastly improved the shifting on this KX500 BEAST!!!
Thanks Luke!
Unfortunately, the gas cap got scratched during shipping,
but after a few friendly emails, the problem was resolved perfectly for both sides.
Friendly service, quick solutions, absolutely reliable
Top-notch shop👍
Everything I have received from TSO has been excellent, I was excited to see TSO had the pressure plate because they was the only ones , thanks for amazing products and service
Very well made pipe fits good have not been riding yet so don’t know if it leaks out two stroke oil like the stock one does we will see when it gets cool out for riding
Very quick shipping, and super pleased with the quality of this stator cover! The anodized black blends nicely with the satin black powder coat on my KX500 engine.
Quality parts!!! Very happy with what I received for the money!! Fit and finish is top tier. Also happy to support a company who is helping keep these two strokes alive! I will be back for more parts soon!
Bearings were a perfect fit. A couple of shaft bearings were on back order, which I reicieved shortly after a majority of my orders arrived. Quality of everything is immaculate I would certainly do business with Luke again. I honestly wish I could have purchased the billet cases for my kx500af build after seeing the precision on the covers and head. Highly recommend TSO
Haven't installed these parts yet but the maching and quality looks better than OEM. Looking forward on trying out their other specialized parts offered.
I ordered the case saver for my 98 kx250, the price of the TSO case saver was very close to the same as the original kawasaki one.
The difference is huge, The TSO case saver is made of stainless steel for extra strength and great looks.
Shipping and customer service was very fast and included mounting hardware.
First time I ordered from TSO, but it won't be my last.
Thanks TSO for offering a quality part and great customer service!
So the cylinder head is immaculate and performs perfectly with the decompression valve. Much much easier to start this 500cc 2 stroke. I just wish I the decompression valve was coming off the side instead of straight out the top. Decompression valve creates interference taking out the spark plug when everything is mounted and the bike is together. Purchased a new wrench to remove the spark plug and all is ok. Overall happy 😁