The clog in the fuel line at the fuel tank was the issue! Ran the mower for 2 hours with blades engaged and it didn’t think about dying once! Thanks for all the help!
I do have one other question… I’m currently running the engine around 3200 rpms but I’d like to get closer to 3600. The governor screw is all the way out already but I can manually manipulate the throttle (rod?) to increase rpm more. I know not to exceed 3600 but what adjustment do I need to make to get to this 3600 mark?
first things first..make sure the rpm gauge is accurate. Sometimes they don't work properly or the sensor wire is not attached properly or worn down....verify this if you can with a separate tach meter...they are cheap. But if you don' t have a separate tach meter to verify then skip this and do following to rule out the max rpm issue:
most of wide open throttle and and top rpm is related to a combination of several things, always start with the fundamentals:
1. is the throttle cable moving the governor arm to throttle linkage all the way and that results in the throttle carb valve to open all the way? check all linkages and the damping spring from governor to throttle valve.
2. does the choke valve open all the way and close all the way..?...inspect it and make sure that valve moves freely and the spring is rotating it back to full open rotation when choke is off? if the spring is missing or the choke valve cannot move to the wide open position with choke off, then max rpm will not happen...air fuel mixture becomes too rich. if you take the spring off with ENGINE OFF, the choke valve should open and close all the way back and forth and move freely.
3. quality of fuel? Any possibility of water or old gas? Remove fuel line from carb ENGINE OFF, and check for any contamination or water in the catch container? I use a glass jar...easier to inspect fuel.
4. air cleaner blockage? remove air filter temporarily and see if rpm's go up. If they do, clean air filter or replace.
5. make sure the fuel pump works properly...performing a fuel flow test with the fuel line removed from the carb into a catch container...it should be a good steady flow. If not, check filter and fuel pump.
there is a hidden air needle valve in the carb..usually it's cover by a welch plug. It's factory set and almost never needs to be adjusted. I would leave that alone...clean the carb and remove the bowl and make sure the float and needle valve are clean and the float needle valve has no corrosion on the tip...sometimes it has a little rubber tip...make sure that is not worn down or borked.
while you have the carb bowl off, inspect the anti back fire solenoid ...WITH ENGINE OFF/KEY OFF, you should be able to use your finger to depress the pin into the body of that device. If you cannot depress it by hand, clean that up with carb cleaner or brake cleaner. Then do this...FROM KEY OFF, TURN KEY TO RUN ..NOT START..ONLY TO RUN. You should see the anti back fire solenoid click and retract the pin back into the device and it should stay retracted. TURN KEY FROM RUN BACK TO OFF...pin should pop back out. If the anti back fire solenoid does not operate correctly after cleaning it...consider snipping the pin off entirely...your engine does not really need this device to operate...it's a common problem these devices fail..and that can cause fuel delivery problems. If you are concerned about back fire, move throttle to idle before key off.
and lastly this: kolher engines are manufactured to to meet a lower industry standard than compared to kawasaki. What this means is that engine horsepower (and rpm) are going to vary..because the reality is that the lower standard involves manufacturing quality assurance for each and every engine to be met. As a consequence...a kohler engine "rated" at say 18 horsepower might be only 17 or even 16...whereas a kawasaki engine, factory fresh will always be AT LEAST the rated horsepower because kawasaki manufactures its engines to meet a higher industry standard. This is one of the reasons why kawasaki engines are more expensive that kohler. Kohler because they only meet a certain lower standard means that "rated" rpm may never be possible in any particular individual engine. There is nothing inherently bad about this but it is something to realize when dealing with kohler engines. And it's one of the many factors that has influenced me to only use kawasaki engines in my machines. Not the only factor, but given I would prefer to have 23 horses and nothing less and not have to be concerned about engine performance over time, I stay away from kohler. I have a small side hustle doing mower and machine repairs. It's common to see kohler engines not produce rated rpms. With Kawasaki...that can happen, but it's usually after long hours or when something isn't right with the machine. It's still worth checking the things I listed about with the kohler engine though...just be aware that for every kohler engine, even factory fresh, you may never get rated rpm or rated horsepower. it's just the nature of how they manufacture to a lessor industry standard. still good engines...just not my cup of tea. your mileage may vary
