Whats it all about ?????

Over 30 years of buying, breaking, building, cutting, welding, riding and selling greasy old mo'sickles. Bare bones bikes from the middle of nowhere!

Wednesday, 26 May 2010

BlackBob goes for a tune up




Ive been a bit unhappy with BlackBob's performance lately, theres a real flatspot in the midrange and I reckoned the motor was running way too lean. Tonight we paid a visit to Chap Middleton at Highland Motorcycle Dynos, a few runs on the bench a change of main jet from a 120 to a 134 and lifted the needle one notch - what a difference! 8-)

Kinda weird watching your bike doing 85mph on a bench, max power shown at the back wheel so far is 33bhp

Original specs for a TR6 motor say peak power at the crank is 42bhp at 6500rpm, we weren't revving too high because the engine's not fully run in yet (since fitting the Morgo kit) Now its running smoother I'll put some milles on, then go back and get a proper readout. The computer doesnt llike the Hunt race magneto so we couldnt get the rpm readout hooked up.
We did find that it runs lean on one cylinder and rich on the other, being single carb we had to settle with somewhere in between for both. Chap reckons there may be a fair amount of tuning available by altering exhaust length.