Loss of power for a few secs seems better when driving harder

this ones doing my head in guys my bike starts first time every time and runs very well ,but when i ride it goes great for a while then for no reason wham!!! loss of power for a few secs then it picks up again and can do this for some time ,but it does seem better when i ride it harder .ive cleaned all the battery connections and its still the same ,fitted new spark plugs ,gave the air fillter a bath so its very clean .

i cant think what the hell it is . the only thing thats not working is the speedo it packed in a few months ago after i got home from the last scottish rideooooot to oban could this be linked to anything that would give me my power loss problem ?

only thing ive done to the bike is fit a scotoiler could it be a vacuum problem ? could it come from the vacuum and only on 1 cylinder giving the problem.
i realy need to get this sorted as its a pain in the *** .

mods are cams pc3 dyno leoV-*** rsv mille 2000 v reg sexy black

hi bud was told by the last owner that the camshafts were not standard thats all he knew as he got the bike from his mate when he went to work abroad and it was him that done all the mods to the bike so i aint got a clue what cams are fitted sorry.

i will unplug the oiler and see it it helps the running cheers bud:thumbup