O.S. Carb Question
#1
O.S. Carb Question
I know O.S. has a dozen different carbs for the .21's. They seem to go up in alphabetical order 21c-21? Can anyone tell me the difference between a 21H and a 21J carb? I see the 21H was used on the speed motors but now I'm seeing a 21J carb is out. Is the 21J the latest and greatest or ? Thanks.
#3
I think the only difference is the location of the idle screw.
#5
as far as performance goes they both work identical i had both on my old speed. it is a tuning issue. with the 21H the idle screw is underneath so when you need to adjust your idle it is a pain in the @#$ to get a screwdriver in there. with the new 21J it is much easier to adjust the idle now that it is relocated up on the back side of the carb