KB PERFORMANCE - KB258.030 - Hypereutectic Piston Kit - '84-'99 Harley-Davidson FXRS-Conv Low Rider Sport Convertible, Sport Glide Grand Touring
This .030-over Hypereutectic Piston Kit from KB Performance is machined from T-5 heat-treated 390 alloy for '84-'99 Harley-Davidson engines, diamond-cut to within a gram of weight and half a thousandth of an inch piston to piston. That tolerance allows a tighter install than typical replacement pistons, reducing piston rock and improving ring seal, though KB's instructions on clearance and top ring end gap should be followed given the alloy's thermal conductivity. Includes two pistons, pins, spiral-lock clips, and Hastings moly rings; rings and pin lock rings are 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: 80"
- Compression Ratio: 8.6:1
- Riding Style: Street
- Bore - Oversize: +0.030"
- Bore Size: 3.498"
- Displacement: 1340 cc
- Piston Material: Hypereutectic Alloy
- Units: Kit
- Product Name: Piston Kit
Frequently Asked Questions - KB PERFORMANCE - KB258.030 - 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.
