well thought i would let you know the results of the changes I have made on my bike in measured terms ie on a dyno, The bike is a r80gs 1991 model,to save you checking backover to previous stuff i wrote - it has the following engine mods, siebenrock 1000 upgrade,K&N air filter, twin plugged heads, lightly gas flowed, standard 32 mm carbs and valves, 1 piece rocker guides (really quieten down rocker gear noise and save adjusting for rocker shaft play - nice kit), balanced conrods, (balanced over entire length to match each other),matched pistons, balanced crankshaft, heavy duty clutch, siebenrock sgs2 high torque exhaust, 296 enduro camshaft, bronze bush cam bearing, endurolast alternator and twin plug ignition system, gearbox 1st gear 5%lower, top gear 5% higher, Now she is running near perfect with electrics for the spark from the endurolast ignition ,NGK bp6 iex plugs, ngk plug caps copper core race HT leads, twin tower Dyna coils. After all that work Phew! the figures on paper are not spectacular but riding the bike is very much a different story to a standard 800gs or 100gs.

Dyno measured power at the back wheel, 52.76 hp at 6000 revs (65.95 at the crank - approx calculation some internet guides would have calculate it to be 72.01hp),
Back wheel measured Torque 72.08nm (53.16ft/lb)at 3400 revs However Torque reaches 66.44nm (49 ft/lb) at 2400revs reaches oits peak at 3400 where it continues pulling at 72.8nm through to 5800revs when it tails off slightly to 44nm by 7000 revs - but then the max hp kick is taking over pulling the bike forward with a descent surge.
In rideable terms the engine is very quiet (i mean as quite as I have ever heard an airhead), very smooth all through the rev range and so tractable and usable at all road speeds and will happily cruise at 90mph and pull top gear cleanly from 1800 revs without protest on a level tarmac road and about 2400 when under more load or on an uphill gradient.

Fuel mix ratio stays fairly steady throughout the entire rev range at about 14.6 with only slight variation at the bottom end where it dips to around 13 for the transition at 2,500/3000 revs maybe the next size idle jet would smooth that out but I dont think its worth changing for the tiny difference it would make.

Fuel consumption appears to be steady around the 50 /52 mpg (5.6 litre per 100km) in normal riding.

Bye the way kept the K&N air filter - bike kickstarts again from cold - turned out I had the idle circuit a touch to lean originally and more so after putting in the K&N so now its just fine.