7841 Morrison St. · Morrisonville WI 53571 · 608-842-0680

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YZ144 Big Bore/Stroker

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YZ144 Big Bore/Stroker

Please call to order 608-842-0680

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Availability: In stock.

$1,125.00

Quick Overview

YZ144 Specifications:

Fits 2005-Current YZ125

Call for bolt-on pricing

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$1,125.00
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Product Description

Bore: Yes
Stroke: Yes
Actual Displacement = 144.08cc

Engine Modifications Required:
Cylinder: Bore, Port and Replate with Apticote 2000 ceramic bore coating.
Power Valves: Machined to match big bore ports.
Head: Rechamber to work with the Big Bore piston and stroker crankshaft. 100 octane suggested for most conditions.
Crankshaft: Stroker Crank Pin Included.
Crankcase: Crankcase mods required to clear stroker crank. Click Here for picture.
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: Core parts subject to inspection before credits will be issued.

Notes: This is the ONLY YZ125 stroker kit we will sell as a "Bolt On" because the crank does not require balancing.
Notes: The YZ125 does not work the greatest at 144cc when it is all done with bore. The transfer ports drop too much and it gets flat feeling with alot of torque and no rev. The Max Power YZ144 uses a smaller 56mm bore combined with a stroker crank modification. The piston is much lighter than stock so balancing the crank is not necessary. A bore only YZ144 is not even close to the power of this kit. The Max Power YZ144 has a nice torquey feel on the bottom and just screams all the way past where a stock YZ125 falls off the pipe. This kit makes an awesome schoolboy class weapon. If Yamaha built a YZ144 they would do it like this.