KB PERFORMANCE - KB305.040 - Hypereutectic Piston Kit - '84-'99 Harley-Davidson FXRS-Conv Low Rider Sport Convertible, Sport Glide Grand Touring
For a .040-over rebuild on '84-'99 Harley-Davidson engines, KB Performance's Hypereutectic Piston Kit uses T-5 heat-treated 390 alloy diamond-machined to within a gram and half a thousandth of an inch across the set. The tight tolerance supports a closer install than standard pistons, cutting piston rock and improving ring seal - KB's instructions on piston clearance and top ring end gap matter given the alloy's thermal properties. Two pistons, pins, spiral-lock clips, and Hastings moly rings are included; rings and pin lock rings sold separately.
Features
- Manufactured from high-strength, T-5, heat-treated, 390 hypereutectic aluminum alloy
- Allow a tighter fit and longer piston and ring life
- Diamond-machined pistons are held to plus or minus one gram weight and less than one-half-thousandth-inch (.0005") tolerances from piston to piston
- Each kit contains two pistons, pins, spiral-lock pin clips and Hastings moly rings
- Replacement piston rings and pin lock rings available separately
- KB pistons can be installed tighter than other pistons. This results in less piston rock and better ring seal. Please read instructions included with piston for correct piston clearance.
- Due to the thermal conductivity and design of KB pistons, special attention is required to the top ring end gap. Please read instructions furnished with piston for correct ring installation.
Specs
- Displacement: 1340 cc
- Riding Style: Street
- Compression Ratio: 9.6:1
- Product Name: Piston Kit
- Units: Kit
- Bore - Oversize: +0.040"
- Bore Size: 3.498"
- Displacement: 80"
- Piston Material: Hypereutectic Alloy
Frequently Asked Questions - KB PERFORMANCE - KB305.040 - Hypereutectic Piston Kit - '84-'99 Harley-Davidson FXRS-Conv Low Rider Sport Convertible, Sport Glide Grand Touring
How do I know if this part fits my vehicle?
Check the fitment information listed on this page against your exact year, make, model, and (where applicable) trim, engine size, or configuration. If your exact vehicle isn't listed, or you're not sure, use the product chat on this page or contact our support team before ordering - we're glad to help confirm fitment.
What does it mean if a product is listed as universal fit?
Universal fit means the product is designed to work across a range of vehicles, not that it's guaranteed to fit every one. Compare the listed measurements, mounting requirements, and connector or hardware specs against your specific vehicle before ordering, since some installations may need additional hardware or minor fabrication.
Where can I find installation instructions for this product?
General installation notes are provided above where available. For detailed step-by-step instructions, refer to the manufacturer's documentation included with the product, or use the product chat on this page for questions about difficulty, required tools, or whether professional installation is recommended.
What if I have more questions about this product?
Use the product chat on this page for fitment, specs, installation, and compatibility questions, or contact our support team directly for help before you order.
