637 and 950

kanshosensui · Post by **kanshosensui** » Thu Sep 11, 2008 4:01 pm

What is the dimension of the throttle body on the YS637 and the YS950? I am trying to avoid having to remove the carb to find out. If anybody knows I would appreciate hearing from them. Thanks

Post by **wesk** » Mon Sep 15, 2008 12:06 am

They are different. M38 uses the YS637S which has the mounting bolts on 2 3/8" centers and a throttle body throat diameter of 1 1/4". The M38A1 uses the YS950S which has the mounting bolts on 2 11/16" centers and a throttle body throat diameter of 1 1/2". Hope this helps.