Wiseco Piston Kit 81.50mm 10.25:1 - Honda ATC350X, TRX350 Foreman (1985-1989)
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81.50mm bore, +0.50 over • 10.25:1 compression
Important: This is an oversize piston. Your cylinder must be bored to 81.50mm before it will fit. If your cylinder is still standard, order the standard bore version.
✓ Fits
- 1985-1986 Honda ATC350X
- 1986-1989 Honda TRX350 Foreman
- Stock bore and stroke 81 x 68mm • 350.4cc • 10.25:1 compression
- This listing is 81.50mm bore, +0.50 over
✓ Features
- Forged from high-silicon aluminum alloy, not cast, for maximum strength and dependability
- Forging design and skirt profile shaped to deliver horsepower and torque across the range
- Handles heat and detonation far better than the original cast piston
- Better heat transfer out of the crown means longer service life under sustained load
- CNC machined for consistent sizing with no variation part to part
- 10.25:1 compression
- Uses circlip CW21
- Made in the USA
✓ What's Included
- Forged piston
- Piston rings
- Wrist pin
- Circlips
Ships fast from DuneGoonShop!
📦 Shipping Information
In-stock items ship next business day. ModQuad parts dispatch Monday through Thursday.
Made-to-order and custom powder coat items show their lead time at the top of this page, right next to the truck icon. These are built fresh for you, so timing varies by brand and current backlog.
Need something by a specific date? Call us at 541-668-7503 before ordering and we will check stock and ETA on that exact part. We can often point you to an in-stock alternative from another distributor.
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