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25 hp kawasaki putting out strange rpm's

matthew horner

LawnSite Senior Member
Sanford, NC
My Kawasaki motor on my Hustler super z is (both under load and no load) is running strange. It will go from one rpm to another, as if it is starving for fuel. It has a new carb, and new fuel filter as of a couple of months ago. The range it fluctuates in is withing 300 or so rpm's ,with no input from me. I haven't detected a trend.

Any ideas?

Thanks to all.


LawnSite Fanatic
Try this; While it's fluctuating start applying the choke SLOWLY and see it it smooths out. If it does then you most likely have a piece of trash in the carb.

Even though the carb. is recently new it doesn't take but one full-up to contaminate the fuel system. Clean the carb, Check/clean tank, Flush the lines and replace the filter again.