Kohler 20resal 100amp transfer switch RXT will not auto start?

https://www.kohlerpower.com/home/common/pdf/tp6804.pdf

if a lightning strike was anyplace close (30 yds) it's a safe bet your gonna have to replace the control board in generator also Id have a qualifyed tech ck out your auto transfer switch ,I bet he''ll find that you fried your coils on your switch too , do that before changing control board cus if ya hook up a new one to a bad coil ya just bought two of them

Contact Nixon Power Services in TN they can supply you with one

No be careful !!! the muffler is designed to give a certain engine back pressure and emissions. Changing this or piping it out can increase back pressure to dangerous levels. If you build an enclosure make sure the air flow in and out is sufficient and the hot air out does not get sucked back in as cooling air (short cycle) engine damage and fire can result !

Did you check the remote terminals and relay in the ATS, disconnect gen remote wires, kill the ATS brealer and ohm across the start terminals, they should close, if not a relay/control board issue, if they do fault is in wiring or gen control, or incorrect wiring

On exercise it isn't under load, you may have too much gas pressure, have the gas pressure and fuel/air ratio checked on the mixer

Will it start manually? if so remote ATS issue, if not check battery

Is there a fault?? All UL listed generators including Kohler are required to lockout on a fault on shut down. This really sounds like a problem with your 2-wire auto start connection between your automatic transfer switch and genset. RDT model automatic transfer switch it is the 2 middle wires on the green connector and terminals 3&4 in the generator. close to run and open to shut down. Any open at any time will cause the unit to shut down. The 12 will shut down instantly upon an open because your 5 minute cool down is built into the transfer switch.

Call an electrician.