Carb Question ?

which is the smallest carb i should use to get the best out of a metra kit pro race 2 on a Aerox

Is a 21mm carb good or it is too small ?

Thanks

28mm is the most common carb for this kit for the aerox tuners, as the highend kit requires more fuel to perform at full potentioal!, if you plan on using a 21mm carb, an iron kit at least or a mild race cylinder like a polini corsa or mhr replica would be a better choise! Whats the point buying a kit designed for big carbs and slapping a little carb on and limiting the potentional. Hope i helped. Happy tuning.

hi, ive got the same kit on my aerox and its pretty difficult tryin to set it up, im only running a 20.5 at the moment but im planning on either 25/28 with straight mani.. wot variator,clutch and pipe set up have u got.
thanks.

dont be silly


polini use a 21 on there crate evo engine's... a big carb lkets an engine perfrm verry well but smaller carbs ar usually selected fr track or ROADuse as its a litte lespower over a BROADER poweband, keep cooler alot quicker and saves on fuel use.

i used a 17.5 on an evo spec bike... aslong as you dont push the bike into the revs there fine.. a small carb will only run out of puff as the rev's climb over what rhwey would at usual acceleration (asin, when you get to the top of the gearing and keep going rev wise the carb will just run leaner and leaner where a bigger carb will just fuel nicely as the air mass isnt excedding the carbs range) ideal is to overgear the smaller carb so you stay in the revs and spot on wiht the jetting and just run out of power to push the gears (like in a car, you never hit the top of fifth)

its a big trade off between big and small carbs.. smaller isnt always that much slower, somtimes its better (depends how you ride it)

the "usual fitment" is down to sprint use.. yes i use 25/28mm carbs on sprint 70's happily.. its too much for the road.

if you cant set up a small carb on a bike you cant set up any carb on a bike. simple as that really. 21 will fuel nicely on the road and keep life in the cylinder.. 25 will kill fuel but give better fueling and also allow you to push the bike into the limits..or as above use a smaller carb and dont take the piss top end.. or fit a gear up..

up to you, dont for a min think a 21mm carb wont fuel it tho.. had a minimoto engine hitting 14.7 bhp @13,500 on a 21mm phbg. bigger reedblock than any scooter out there and its a 50 (port area of an evo/prorace/mhr team) it ran upto 18,000rpm but was obviously loosing fuel at top so lost power the more it rev'd.. this was running a STATIC ignition (fixed timing, no cdi) so yes quite a mean feat for such a little carb. (thats real bhp.. djhp is 2bhp more so 17+bhp on shiny's dyno as it runs djhp and the one i used was an engine dyno using actual torque output from the crank)

so yes.. use a 21 if you so wish. it will fuel fine aslong as you dont overrun the engine. it will use HALF the fuel of a 25 on the road and live alot longer. its a road bike, keep it that way?

what about a 24mm

??

what about a 24? it 1mm smaller than a 25 and 4mm bigger than a 21 (obviously) if you cat work out the answer from whats above then give up....

minor i thinks you shoudl edit that or get some sleeps

makes perfect sence... ive explained about 25mm carbs, 21mm carbs, 28mm carbs AND 17.5mm carbs..... everyone should be able to work out a 24mm is slightly smaller than a 25 and this effrect would be 1/4 of the loss of the 25 but 3/4 of the gains...

MiNoR cOnFuSiOn said:

4mm bigger than a 21

i thought 21 was 3mm smaller than 24 mate

yeah i wasnt doubting your knowledge for one second mate

just the 24mm carb is surely 3mm bigger than the 21 no?

ye, wrong key.... you get the idea.... not the biggest fan of sleep... blame the mistakes on a lack of drugs