|Bought in September 2008 in Louisa, VA. Had trouble idling, previous owner had only driven for 34 miles then moved up to a ZX9...good luck to him.
Found a mouse nest full of duck feathers in the air filter box, had to vacuum that out and learned why the bike ran a tad *lean* and resolved the idle issue. No damage to the internals, as the metal screen in the intake blocked anything from being ingested. The plugs were NGK's CR7's, which caused some issues with cold starts, notably bucking under load until fully warmed up. Installed some CR8's and now the bike uses significantly less choke and warms up much faster. The only issue with body work was the previous owner smacked the left front blinker into his shed. Had to get a new housing.
Modifications. All are safety related [1 is comfort]
Added extra brake lights, SS front brake line, 2" round mirrors. At the insistence of a friend, I had the seat re-upholstered and added gel packs to make the bike more bearable on long distance rides.
Adjusted valves at 6,500 miles, lubed the suspension at 5,900 miles and replaced the stock tires with Kenda K671's. Fork oil replaced at 9,9xx miles 5.16.10, the last of any factory fluid in the bike. I don't think any previous owners had ever lubed the chain and was stretched enough that I had to install a new chain at 11,300 miles. The stock gearing was changed to 14/42 ratio, and switched to Rotella 15w40 motor oil. At 12,200 miles, new EBC HH front disc brakes were installed.