Craftsman 917.271131 Runs rough, loses power and dies once it gets warm

[callwill]

6 speed 42 inch cut Kohler 16.5 OHV CV16S
Its my brothers, he keeps it at our mothers. Fuel and spark not an issue at least when cold. If it sits a while it can be started and run until the death spiral starts again. I want to help point him in the right direction for parts/fix.

 

[hlw49]

Boy that is a no no CV16S advertised as 16.5 HP. Any way you have to determine why it i quitting spark or fuel.

 

[Cusser]

6 speed 42 inch cut Kohler 16.5 OHV CV16S
Fuel and spark not an issue at least when cold. If it sits a while it can be started and run until the death spiral starts again. I want to help point him in the right direction for parts/fix.

Mine is an LT1000 from 2005, with B&S engine, but I had similar symptoms a decade ago. My manual choke lever would move the cable but the spring in the carburetor was too weak to allow the choke butterfly to return to the "open" position when I manually moved the lever after 5 minutes of running, so mine was running way too rich when warmed up, and would stall out.

Instead of choosing to manually hop out and move the choke with my hand, I installed a 25-cent spring to add more strength to open the choke when I moved the lever from my seated position.

 

[callwill]

Mine is an LT1000 from 2005, with B&S engine, but I had similar symptoms a decade ago. My manual choke lever would move the cable but the spring in the carburetor was too weak to allow the choke butterfly to return to the "open" position when I manually moved the lever after 5 minutes of running, so mine was running way too rich when warmed up, and would stall out.

Instead of choosing to manually hop out and move the choke with my hand, I installed a 25-cent spring to add more strength to open the choke when I moved the lever from my seated position.

No seperate choke lever, its part of the throttle and it seems to work just fine.

 

[callwill]

When looking this thing over it is impossible to tell if it came from the factory with that CV16S or it was a replacement installation.
If a replacement would the original have been a CV16.5S?
My brother has no plans to further investigate until he is done cutting for the season. He gapped the plug to 040(per kohler) thought there is some indication per craftsman that is should be 030.
Are the coils the same? I know he said he bought an air filter for it, but it turned out to not fit the assembly on it, it was too tall and had to get a shorter one...which leads me to beleive it could be a replacement motor with the original shroud in place.
How hard is it to get to the coil?