I helped a friend purchase a 2007 ninja 250R today and the only questionable thing about the bike was valve ticking and a floating throttle. The bike has had 2 previous owners and 5500 miles. The last owner put 500 miles on it over the past 1.5 years.

Maybe the carbs need to be synced or it just has bad gas?

The throttle opens and closes quickly, but the engine will some how hold the revs up around 2krpm for about 2 seconds, even with throttle closed. Then it will gradually go back down to around 500 rpm.

Does anyone know what the remedy might be?

 

check for a vacuum leak as well.

 

When valves tick it usually indicates a timing issue or lean mixture I think. How long has it been since the clearances were checked. My 'o6 was a few thousanths off during my first 1000 miles. I checked it again near 8K and it didn't change much at all.

When it drops to 500, does it stay there? Or does it go back and forth between 500 and 2K?

 

dang, forgot to mention the obvious and to lube the cables as per the manual.