Jonboy wins a lend of the advancer, once the last guy's done with it
Andrew, the ignition advancer's wicked... Don't know how it works exactly, but it's a wee tiny bit of metal the size of a toenail clipping that you stick into the end of something, possibly the crankshaft, and- well, there's dyno charts on the JHS site for it. The part costs £20, but you need a new alternator cover gasket for it, and a special rotor puller tool that cost me £25 IIRC but which is verrrry sloooowly doing the rounds on a permanent lendout...
Basically, a power boost, plus the torque comes on much much earlier in the range. JHS shows a 3hp boost all acrss the rev band, which doesn't totally match my own experience, but then my dyno run in question was made with terrible jetting and so doesn't count. I didn't see anythingon the top end, but the midrange boost is excellent, great for town riding.
May wear the engine faster and increases the likelihood of detonation/preignition/etc, apparently, but I've had absolutely no downsides.
Still no carb balancer, Sid Squid put me off a little as he knows far more about that sort of stuff than me, and then it occurred to me that since it's going in for a rejet once I finally do the cams, the shop'll check all that sort of stuff for me anyway... I'll be looking for an Ebay one, I think.