What combustion byproduct issue, notorious in traditional kerosene engines, does methane combustion largely eliminate?

Answer

Coking, which is the deposition of carbonaceous soot.

The combustion of $ ext{RP-1}$ leads to 'coking'—the buildup of carbon residue inside the combustion chamber and plumbing, necessitating frequent cleaning. Methane burns much cleaner, significantly reducing this issue.

What combustion byproduct issue, notorious in traditional kerosene engines, does methane combustion largely eliminate?
fuelrocketpropellantcombustionMethane