I'm thinking that it probably runs fine up to around 3000 - 3200 and gets worse from there up. Try putting the 160 jets back first and see how it runs. If it's better, take a nice long ride keeping the engine at 4000 or better (use a lower gear if you have to). Then shut the engine down and grab the clutch, stop andtake a look at the sparkplugs. If they have some carbon on them, try maybe 150 jets and see what happens.

Let's hope there's intelligent life somewhere in space 'cause it's buggar all down here. -- Monte Python