Big Bore Kits

Someone once said, "There's no replacement, for displacement". I think they were probably right. I am no expert in thermodynamics, but real useful power generally seems to come from the larger displacement engine. The big bore engine should give more power and torque, installed in the proper manner. Remember though, big bore kits usually mean more heat, so a larger oil cooler is desirable and don't let her 'cook' in traffic.

WISECO PISTON KITS - Probably the most well known of the 'Big Bore' kit suppliers, Wiseco products have a good reputation.

TTS - Supply big-bore kits, here in the UK. But that's not all, so check out their site.

Another interesting developement, is the introduction, by Yamaha, of the XJR1300. This features 'Nicosil' surfaced bores, for cooler running. Whether the cylinder block, pistons etc, could be transfered to the FJ engine, I don't yet know. Though badged as a 1300, the actual displacement is only around 1250cc's. This would be a useful increase for an FJ1100, but any gain over the FJ1200's (1188cc) displacement is bound to be limited.


The FJ lump lives on in the XJR1200 & 1300


PRO CHASSIE RACING BIG BLOCK - Rodney Mumford, whose bikes here ; produces as far as I know, the only big block for the FJ. I would hazard a guess that they are mainly suited to drag racing applications. Details can be found at Rodney's website :- Pro Chassie Racing