AFB Motorcycles

The use of these 3 7/8" bore pistons with stock 4" stroke enlarges the capacity of your Twin Cam engine from 88 to 95CI with the use of bored to size stock cylinders. Available with 9:1 or 9.5:1 compression ratio, which can be used with the stock ignition on both carburetor and EFI equipped models, or domed with 10.5:1 compression ratio, which requires the use of a High-Performance ignition system, such
as our Dyna ignition ZPN710586. These Big Bore kits contain a pair of Wiseco forged pistons, a Hastings ring set, chrome wrist pins, circlips and a top end gasket kit. Ring sets are separately available.

Incomplete: Kit supplied without gasket kit
Sold as it is, no stock return, no warranty


Big Bore kit piston kits
Compr. 10.5:1 Bore Size
+.010" 732711B

Piston dome specification
All valve pocket specifications are measured from deck height
Comp. Ratio Dome Volume Intake Pocket Exhaust Pocket
Depth Diameter Depth Diameter
9:01 -2CC -.161" 2.000" -.158" 2.000"
9.5:1 +4.6CC -.183" 2.000" -183" 2.000"
10.5:1 +15CC -.161" 2.000" -.158" 2.000"

Recommended Retail Prices include 20% sales tax.

Prices exclude shipping, import duties and installation.

Prices are based on EUR to GBP interbank rates obtained daily. The interbank rate is the rate that banks trade currency to each other. These prices must be used as a guide.