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JE, Yamaha, 86.00 mm Bore, 4 Cyl. Kit


SKU: 292314

JE, Yamaha, FX SHO 1800, 9.50:1, 86.00 mm Bore, 4 Cyl. Piston Kit

As the leader in forged racing pistons, JE Pistons has applied over 75 years of experience to its wide range of premium forged powersports pistons. Covering everything from the lake to the mountains, JE’s watercraft and snowmobile pistons are engineered, forged and machined 100% in the USA. JE Pistons are designed for each specific engine and riding application to provide the ultimate combination of durability and performance. The heavy engine loads, excessive operational heat and high cylinder pressures of these engines were taken into account with every JE piston design, and the performance is proven with every handful of throttle. Equip your PWC or sled with the best in forged pistons.

  • Forged in the USA using 2618 aluminum, yielding high tensile strength needed for high-demand performance applications
  • Designed specifically for each engine and use application to provide optimized performance durability
  • Proprietary Forged Side Relief (FSR) forging design minimizes friction and power loss with reduced skirt width and saves additional weight with a shorter wrist pin
  • Includes high-quality wrist pins, locks, and JE Pro Seal premium piston rings
  • Made 100% in the USA

GTIN: 00193564220721

Weight 4.300 lbs
Dimensions 5.000 × 9.000 × 5.000 in
Cylinder Head


Bore Diameter

86.00 MM

Compression Ratio Actual


Piston Head Type


Piston Volume

33.50 CC

Piston Material


Forging Type


Piston Average Weight

321 GR

Ring Set Included


Top Compression Ring Thickness

0.0400 IN

Second Compression Ring Thickness

0.0480 IN

Oil Ring Thickness

0.111 IN

Wrist Pin Outer Diameter

0.866 IN

Wrist Pin Wall Thickness

0.170 IN

Instructions: Enter a value in the un-shaded boxes below as they pertain to your engine.
Note: For pistons BELOW the block @ TDC – value in box must be a NEGATIVE number (-0.000)
Note: For pistons ABOVE the block @ TDC – value in box must be a POSITIVE number (0.000)
Note: For a DISH piston – value in box must be a NEGATIVE number (-0.0)
Note: For a DOME piston – value in box must be a POSITIVE number (0.0)
Note: Manipulate the DOME/DISH & PISTON to DECK volumes to get the ratio you want.
Enter the number of cylinders of your engine
Finished bore of your engine
Stroke of your engines crankshaft
Rod Length
Ctr. to Ctr. length of your connecting rods
Gasket Bore
Head Gasket bore diameter
Comp. Gasket
Compressed Head Gasket thickness
Block Deck Height
Center of main bearing bore to top of block
Top Ring Down
Top of 1st ring to top of pistons(FLAT)
Chamber Volume
Cylinder Head chamber volume in CC’s
Dome/Dish Volume
DOME (-) or DISH (+) vol. (theoretical) in CC’s
Piston to Deck
Top of BLOCK to top of piston (FLAT) @ TDC
Click “Calculate” for dimension results.
Total Volume
Cylinder Volume
Total cylinder volume in CC’s =
Clearance Volume
All effective vol. above block deck @ TDC in CC’s =
Gasket Volume
Volume of your head gasket in CC’s =
Top Ring Volume
Total volume above the top ring @ TDC in CC’s =
Deck Volume
Volume of area above the pistons @ TDC in CC’s =
Piston Top Land
Piston top land diameter for volume calculations =
1/2 Stroke
1/2 stroke of your engine’s crankshaft in inches =
Compression Ht.
Ctr. of piston pin to top of piston (FLAT) in inches =
Cubic Inches
Cubic inch displacement of your engine =
For the given dimensions, your compression ratio