kawasaki not running right

[D2hornets58]

I have a 15 hp kawasaki engine on a 36 inch wright velke walkbehind mower. It runs perfectly fine with the blades on but once i turn the blades off, the engine revs up and down. It sounds like it might not be getting gas or something because it will rev up then down and just keep doing it. Once I turn the blades on the engine smoothes out and runs fine untill i turn them off again. any ideas what this could be????
Thanks

 

[dodgefate]

I think what you are describing is somthing people call hunting for an idle. DOnt know much about Kawasaki motors, but usualy all engins have some sort of "Sail Switch". Folow the links from teh carb back to a metal arm. THe slightest adjustment will do a lot try searcing for sail swithc adjustment or governer.....

 

[ddorr]

I have a John Deere with a Kawasaki 17hp engine and had the same problem. I solved mine by taking the carb apart and soaking in carb cleaner over night. you have to get all the jets out and the emulsion tube out and realy give it a good cleaning. After that it ran fine and perfect low speed idle. Good luck with yours.