Small Engines (Lawn Mowers, etc.): Throttle adjustment, cub cadet src 621, lever moves

Question
I have a cub cadet src 621 self propelled push mower with a kawasaki 6.5 HP OHV engine.  I sent my mower to be tuned up. When I got it back it doesn't run as fast as it did before.  I can't find the throttle adjustment for the engine.  I can find the throttle and move it and the engine speed increases, but I didn't find a way to hold that adjustment.  Any suggetions ?

Answer
Hi Mark,

If you recently had it worked on, the shop should solve the problem at no cost.  Otherwise, if the speed lever moves and will not hold the rpm's, see if you can tighten the nut that attaches the lever.  If that isn't an option, look for another nut that you can tighten to keep the cable from slipping.

Let me know how you make out.
Michael