Click here for more performance options for your YZ85
YZ90 (National Engine) Stroker
| $1725 | Send us your engine and get a 90cc stroker kit installed. |
| $1400 | Spare YZ105/112 top end for later use in supermini classes. (prices vary by year) |
| $100 | Optional Xtreme coated head and piston |
YZ90 Stroker Specifications: |
Fits 2001-2008 YZ80 and YZ85 |
| Bore: No | Stroke: Yes | Actual Displacement = 89.18cc |
| Engine Modifications Required: | |
| Cylinder: | De-Bore, Port and Replate with Apticote 2000 ceramic bore coating. |
| Power Valves: | N/A |
| Head: | Rechamber to work with the stroker crank. 100 octane suggested for most conditions. |
| Crankshaft: | Stroked and balanced. |
| Crankcase: | Modified to clear stroker crank. Additional case mods needed to clear YZ112 Piston. |
| Blueprint: | Calculate deck height, squish clearance, trapped volume, port timing and compression ratio and list on your perminant Spec-Sheet. |
Notes: This kit requires you to send us your entire engine for modification, with kickstarter and shifter.
Notes: This is a national level engine package. The power delivery is designed to build confidence for young riders. It delivers torque and hook up that are un-paralleled in the industry that carrys to a screaming top end pull. This kit just makes all riders faster because it is smooth, easy to ride, and does not fall off the pipe like other engines out there.
Notes: This is the same bottom end as our YZ105 and YZ112 kits. We can also build you a YZ105/112 top end for later use in the supermini classes.
Notes: Prices listed are to install stroker kit parts in good condition engine. Should your engine need rebuild parts there will be additional charges. We will call for approval before we install any parts that will have additional charges. (example: rod kit, mains, main seals, trans parts)
Click Here to order this kit now!
| $685 | We Modify your top end. |
| $760 | Exchange top end - Call for availability - Additional Charge |
| $1275 | "Bolt On" - Includes Cylinder, head, and power valves (prices vary by year) |
| $100 | Optional Xtreme coated head and piston |
YZ92 Big Bore Specifications: |
Fits 2001-Current YZ80 and YZ85 |
| Bore: Yes | Stroke: No | Actual Displacement = 91.99cc |
| Engine Modifications Required: | |
| Cylinder: | Bore, Port and Replate with Apticote 2000 ceramic bore coating. |
| Power Valves: | N/A |
| Head: | Rechamber to work with the Big Bore piston. 100 octane suggested for most conditions. |
| Crankshaft: | No crank mods required. |
| Crankcase: | No crankcase mods required. |
| Blueprint: | Calculate deck height, squish clearance, trapped volume, port timing and compression ratio and list on your perminant Spec-Sheet. (Some operations with install only) |
Notes: This kit requires you to send us your cylinder, head, and powervalves for modification.
Notes: Core parts subject to inspection before credits will be issued.
Click Here to order this kit now!
| $805 | We Modify your top end. |
| $880 | Exchange top end - Call for availability - Additional Charge |
| $1400 | "Bolt On" - Includes Cylinder, head, and power valves (prices vary by year) |
| $100 | Optional Xtreme coated head and piston |
YZ98 Big Bore Specifications: |
Fits 2001-Current YZ80 and YZ85 |
| Bore: Yes | Stroke: No | Actual Displacement = 97.65cc |
| Engine Modifications Required: | |
| Cylinder: | Bore, Port and Replate with Apticote 2000 ceramic bore coating. |
| Power Valves: | N/A |
| Head: | Rechamber to work with the Big Bore piston. 100 octane suggested for most conditions. |
| Crankshaft: | No crank mods required. |
| Crankcase: | No crankcase mods required. |
| Blueprint: | Calculate deck height, squish clearance, trapped volume, port timing and compression ratio and list on your perminant Spec-Sheet. (Some operations with install only) |
Notes: This kit requires you to send us your cylinder, head, and powervalves for modification.
Notes: Core parts subject to inspection before credits will be issued.
Notes: This is an entry level engine package that has excellent power delivery for the supermini classes. It holds it's own against YZ105's and YZ112's.
Notes: It can be later stroked to 105cc with head mods.
Click Here to order this kit now!
| $805 | We Modify your top end. |
| $880 | Exchange top end - Call for availability - Additional Charge |
| $1400 | "Bolt On" - Includes Cylinder, head, and power valves (prices vary by year) |
| $100 | Optional Xtreme coated head and piston |
YZ103.5 Big Bore Specifications: |
Fits 2001-Current YZ80 and YZ85 |
| Bore: Yes | Stroke: No | Actual Displacement = 103.48cc |
| Engine Modifications Required: | |
| Cylinder: | Bore, Port and Replate with Apticote 2000 ceramic bore coating. |
| Power Valves: | N/A |
| Head: | Rechamber to work with the Big Bore piston. 100 octane suggested for most conditions. |
| Crankshaft: | No crank mods required. |
| Crankcase: | Crankcase mods required to clear piston. |
| Blueprint: | Calculate deck height, squish clearance, trapped volume, port timing and compression ratio and list on your perminant Spec-Sheet. (Some operations with install only) |
Notes: This kit requires you to send us your cylinder, head, and powervalves for modification.
Notes: Core parts subject to inspection before credits will be issued.
Notes: This is an entry level engine package that has excellent power delivery for the supermini classes. It holds it's own against YZ105's and YZ112's. Many builders call this a 105cc kit.
Notes: It can be later stroked to 112cc with head mods.
Click Here to order this kit now!
| $1875 | Send us your engine and get a 105cc stroker kit installed. |
| $ | |
| $ |
|
| $100 | Optional Xtreme coated head and piston |
YZ105 Specifications: |
Fits 2001 - Current YZ80 and YZ85 |
| Bore: Yes | Stroke: Yes | Actual Displacement = 105.00cc |
| Engine Modifications Required: | |
| Cylinder: | Bore, Port and Replate with Apticote 2000 ceramic bore coating. |
| Power Valves: | N/A |
| Head: | Rechamber to work with the stroker crank. 100 octane suggested for most conditions. |
| Crankshaft: | Stroked and balanced. |
| Crankcase: | Modified to clear stroker crank. |
| Blueprint: | Calculate deck height, squish clearance, trapped volume, port timing and compression ratio and list on your perminant Spec-Sheet. |
Notes: This kit requires you to send us your entire engine for modification, with kickstarter and shifter.
Notes: This is a national level engine package. The power delivery is designed to build confidence for young riders. It delivers torque and hook up that are un-paralleled in the industry that carrys to a screaming top end pull. This kit just makes all riders faster because it is smooth, easy to ride, and does not fall off the pipe like other engines out there.
Notes: Prices listed are to install stroker kit parts in good condition engine. Should your engine need rebuild parts there will be additional charges. We will call for approval before we install any parts that will have additional charges. (example: rod kit, mains, main seals, trans parts)
Click Here to order this kit now!
| $1975 | Send us your engine and get a 105cc stroker kit installed. |
| $ | |
| $ |
|
| $100 | Optional Xtreme coated head and piston |
YZ112 Specifications: |
Fits 2001 - Current YZ80 and YZ85 |
| Bore: Yes | Stroke: Yes | Actual Displacement = 111.27cc |
| Engine Modifications Required: | |
| Cylinder: | Bore, Port and Replate with Apticote 2000 ceramic bore coating. |
| Power Valves: | N/A |
| Head: | Rechamber to work with the stroker crank. 100 octane suggested for most conditions. |
| Crankshaft: | Stroked and balanced. |
| Crankcase: | Modified to clear stroker crank and larger piston. |
| Blueprint: | Calculate deck height, squish clearance, trapped volume, port timing and compression ratio and list on your perminant Spec-Sheet. |
Notes: This kit requires you to send us your entire engine for modification, with kickstarter and shifter.
Notes: This is a national level engine package. The power delivery is designed to build confidence for young riders. It delivers torque and hook up that are un-paralleled in the industry that carrys to a screaming top end pull. This kit just makes all riders faster because it is smooth, easy to ride, and does not fall off the pipe like other engines out there.
Notes: Prices listed are to install stroker kit parts in good condition engine. Should your engine need rebuild parts there will be additional charges. We will call for approval before we install any parts that will have additional charges. (example: rod kit, mains, main seals, trans parts)