The RM series is a model range of two-stroke motorcycles manufactured by Suzuki. The letters "RM" stand for "Racing Machine" and the motorcycles produced with this prefix in their model names are suited to use in motocross racing. The first in the range was introduced in 1975 with the RM 125M, This bike was plagued by mechanical issues (nearly all seized) and a half year model, the RM "S" was rushed out along with a kit of the "S" changes for M owners.
Suzuki's RM series, which includes models like the RM 125M, was created to compete in motocross racing.  The first model, the RM 125M, had significant mechanical problems (many seized) and a revised version, the RM "S," was released quickly with modifications for existing RM 125M owners.