If anyone is interested in "popping in" a set of larger carbs, here is some interesting info...
I measured the inner diameter (ID) and outer diameter (OD) of my 31mm, 34mm and 38mm carbs.
Here's what I found...
ID OD
31's 31mm 40mm
34's 34mm 40mm
38's 38mm 46mm
So, I didn't have to "spray the intake boots with WD-40 and squeeze them in" as some have suggested. The 34mm's just popped right in. The 38's however...
I'm used to hearing "that's too big for that hole, it won't fit"
I measured the inner diameter (ID) and outer diameter (OD) of my 31mm, 34mm and 38mm carbs.
Here's what I found...
ID OD
31's 31mm 40mm
34's 34mm 40mm
38's 38mm 46mm
So, I didn't have to "spray the intake boots with WD-40 and squeeze them in" as some have suggested. The 34mm's just popped right in. The 38's however...


