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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 28106
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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My exmark looses power when I turn on the blades. Why?

Customer Question

My exmark looses power when I turn on the blades. Why?
Submitted: 2 years ago.
Category: Small Engine
Expert:  Curtis B. replied 2 years ago.
Welcome to JUST ANSWER small engines, let me try to help you !! Engine make and model? Single cylinder or twin? If twin engine, do a cylinder balance test. Loosen the spark plug wires, then with engine idling, pull off one spark plug wire at a time, both cylinders should be equal. If engine dies when one wire is removed, the opposite cylinder is not firing!
Customer: replied 2 years ago.
I just got the mower back from having the engine rebuilt. I also have a new battery on the mower. Taking the spark plugs off did not cause the mower to quit.
Customer: replied 2 years ago.
The place that rebuilt the engine also replace an electrical connection on the clutch.
Expert:  Curtis B. replied 2 years ago.
Does engine die, or just loads up and runs weak? New fuel filter, new air filter? Good fuel flow to the carburetor?
Customer: replied 2 years ago.
Sometimes it stalls because running so slow under load, like on a hill. The engine has good power and runs well until the blades are engaged. The engine is a Kohler Command series CH18-26, CH730-750. I don't know where to find the model and serial number off hand. The decals are all worn off. The mower is LZ27KC605. The fuel filter and air filter are new.
Customer: replied 2 years ago.
I will b leaving for mowing shortly. I should be back around 4:00. If you could respond or call about then, I would appreciate it.
Expert:  Curtis B. replied 2 years ago.
Is engine running the correct maximum rpm? It should run around 3200 rpm. If too low, it will bog badly!
Customer: replied 2 years ago.
How do I test the rpm on a mower. I believe I have a timing light for a car.
Customer: replied 2 years ago.
I don't know if I have a tacometer.
Expert:  Curtis B. replied 2 years ago.
Does it sound like it is fast enough?
Customer: replied 2 years ago.
The engine seems to run fast until the blades are turned on then it slows and remains slow for about 10-15 seconds after the blades are turned off and then the speed increases and the mower seems to have power.
Expert:  Curtis B. replied 2 years ago.
Did you run the cylinder test? I think engine is firing only one one cylinder!
Customer: replied 2 years ago.
I took the spark plug wires off one at a time and the engine ran with either one off.
Expert:  Curtis B. replied 2 years ago.
ok, had to ask. governor may need to be set. See page 29 in manual.
Expert:  Curtis B. replied 2 years ago.
http://www.kohlerengines.com/onlinecatalog/pdf/sm_24_690_06.pdf
Customer: replied 2 years ago.
I purchased a new fuel pump today thinking perhaps it wasn't getting enough fuel when the engine was under the load of running the blades as well the hydro pumps to move the machine.
Expert:  Curtis B. replied 2 years ago.
you can try the fuel pump. But the governor may be the answer!
Customer: replied 2 years ago.
Where is the governor and what do I do to test it?
Expert:  Curtis B. replied 2 years ago.
Page 29 in the service manual link I sent!
Customer: replied 2 years ago.
I got the manual. I have quite a few tools, do you think that there is a good possibility that I would have what is needed and be able to do the governor myself or is it best to bring it in and have a professional do it?
Expert:  Curtis B. replied 2 years ago.
You can do it. It is just a matter of moving spring to another hole.
Customer: replied 2 years ago.
I'll try it tomorrow.
Expert:  Curtis B. replied 2 years ago.
Ok, thanks.