hi everyone my mate asked me earlier if a 25ml carb would work on a 70cc runner ?? any help because i havent a clue arc:
well it woud be abit silly on an iron 70 alone, 21 is the biggest i would go with a sport setup. james evo is running a 25 but youve probely seen his setup
Tut-tut everyone...use the search!!!!! Minor covered this very subject just a few days ago 25mm is optimum carb for full throttle performance on a 70cc might be slightly over-kill on an iron sports kit...but for anything else its 25mm!!
38mm i wont waste my time wiyth 21mm carbs. 20.5 or a 25.. even on an iron if setup right will work fine an give more top end.. pain to setup if your a novice tho
its personal preference at the end of the day...dont forget you get less throttle response with very big carbs...As the signal at the main jet is weaker due to lower air velocity... A lot of this poor throttle response can be compensated for by set-up...but its much harder than setting up a std carb, and some people cant even get a std carb running right!!! But if its only full throttle power your interested in then economy and response are a trade off you live with
1. its an auto 2. its a scooter 3. why would you care how it rides low revs if its setup right.. jus sayin if im going out to buy a carb for a 70 id just bung a 25 on there.. 20.5 is sweet if one comes up but buying new a 25 is the eway forward. bastard to do the first couple times but once you get round the STRANGE needle positions and idle jets your away. btw a 30 needs a qa throttle and you have top ditch the oil pump (or run it permanantly on full and remove the cable)
these simple set up issues may sound easy to you minor...but ive seen people on forums tie themselves in knots trying to set up a std carb As soon as ive got the readys im gonna give the 25mm carb route a bash
