I use a Kawasaki Prarie (650 cc) to round up cattle with. I believe is was purchased new in 2002.
The last tune up it has had was about 9 months to a year ago.
For a couple of months now I have had problems with it when I want to accelerate. It runs fine when I am at half throttle, but when I need a sudden surge of power and give it full throttle, it spits and sputters and I loose power. When I back off the gas, then it returns to normal.
I was going to replace the fuel filter, only to find that it doesn't have one. I have added some Seafoam to the gas thinking this might help, but to no avail.
Any ideas why it is doing this?

Thank you

 

Main jet in your carb is blocked or loose.

 

Thank you. I'll try that and see how it goes. Never have done this before, so it may take a while. Cattle working for the year is done now, so I should have a little more time on my hands. Need to research the engine and carb.