Bike conked out
 

My 888 strada has conked out twice and won't start until I clean the spark plugs, the electrodes are black. I put the original cans back on 2 weeks ago, replacing the carbons and it has been unreliable since. I check the original bill of sale and it says under optional extras "hi level cans and chip". Does that mean it really won't run very well with the standard exhaust if it has an upgraded chip? Thanks for any suggestions.

Correct, The reason your plugs are black are because the engine is running to rich. Which is down to the fuelling so you need to change the chip.

Have you tried putting the carbons back on? I am surprised that putting the original cans on makes that much difference. How old are the plugs and are they the correct grade?
I have found that using standard cans with a upgraded chip, FIM in my case, creates no running problems at all.

I have switched back to the NGK plugs and fitted a new regulator, when I took out the old ones they were as black as a black thing on the electrode bit. Does that mean it's running too rich?

Yep! Check the air filter as well as the fuelling chip - if it's blocked (dirty) the fueling will be starved of air and therefore too rich (in neat fuel).

Changed the regulator, air filter ok, changed plugs....still no good, bike at duke doctors in Sevenoaks as I am also losing brake fluid on the clutch side, bloke said some seal has gone, as it's placed where all the road crud hits it..never mind