Kohler Command Pro Single Cylinder Horizontal Lifter issue

[Tiger Small Engine]

I think your thought would be acceptable. For the most accuracy of engine health would probably need to do a leakdown test. Worked on a generator a few years back that had a 5% bypass on leakdown but only showed 5 psi on compression gauge. Engine had a clogged spark arrester screen.

Yep, leak down test is the next step. Hydraulic lifters, no hour meter, 19 year old engine. Both my leak down tester gauges broke. Guess I have to buy another one.

 

[smallengineguy]

At that point, I typically roll the engine over by hand until that particular valve is being pushed wide open and let it sit. Over time, that will normally bleed the lifter.

That worked! I left the intake wide open/compressed over night and came out today and it started and ran. Sometimes the basic things work! Thanks VegetiveSteam.

 

[VegetiveSteam]

You’re welcome. Glad it worked. Hopefully it lasts.

 

[grumpyunk]

The lifter was not allowing the oil to bleed when valve pressure was removed from the pushrod. The internals are supposed to move freely, and open the 'capture' chamber so oil can relieve the pressure. When the lobe starts to push on the lifter base, the insides move and close the relief valve and capture a slug of oil. That slug is what makes the insides solid with the lifter body, and thus able to push on the push rod. If the oil gets captured and is not allowed to escape when pressure is relieved, it may pump up and hold the valve open.
Essentially, the lifter was sticking so oil could not leak out(likely to go up the push rod). It broke free and started moving again.
If you look in the Kohler shop manual, it indicates some valves are adjustable, and the clearance must be measured with the lifter bled down completely, The retainer is then tightened to the point a specificed clearance is reached. I do think the procedure is for older models. But, what is an 'older' model? The newer models use the tighen to x.xinch/lb adjustment.
tom

 

[grumpyunk]

Either intermittent valve sticking in the guide, or hydraulic lifter pumping up and not letting the intake valve seat could cause back puffs.
Have you checked the cooling fins for any sort of blockage such as clippings or nests? Has the oil been changed regularly enough that it likely is not causing gummed valve stems/guides, or lifters that may have sticking check valves?
Have not heard much of the rocker studs moving in the cylinder heads on Kohlers, but comparing the height of all would verify they are in place(or all have moved...).
If it is down on power, you might check fuel availability - pump if equipped, filter, fuel line condition and outflow from the tank. Fuel line can decay internally but look perfect on the outside.
When started and warmed up, will the engine increase rpms without hesitation when you move the control from low to higher rpms?
tom

ADDED: You may get more information/response by posting on a twin cylinder post, or posting with that label. This is labeled for singles.