Hitchcocks Royal Enfield 650 big bore kit
Do you feel your Royal Enfield twin is lacking oomph? Royal Enfield specialists Hitchcocks is supplying a 865cc big bore kit to convert the 650 Interceptor and 650 Continental GT. There are two kits available, one requiring the machining of the existing barrels to accept the new sleeves and the other supplied with ready machined cylinder barrels. The big bore conversion is made by S&S Cycle. It converts the 650cc twins to 865cc by taking the standard 78mm bore to 90mm while raising the compression ratio from 9.5:1 to 11:1. This is a bolt on set of machined cylinder barrels with matched pistons ready to fit. A great improvement to both torque and horsepower, with testing indicating a huge 24bhp power boost and much great midrange torque. Hitchcocks suggests that before fitting the big bore kit, buyers should look at replacing the front exhaust pipes and silencers for a less restrictive version and a Dynojet Power Commander. To cope with the extra power, it suggests a clutch upgrade, performance camshaft and air filter retainer. Changing the cylinder head bolts is also recommended! The full kit costs £1740 with the sleeve kit costing £790.80 and the suggestions are in addition. From what we’ve heard from over the pond, it makes an already good bike a very naughty one…