aight i been lookin into a carb for my 75cc kit cuz it runs like shiot and fab5 told me to get the 20mm carb i was like aight i got on ebay found one for 100 bucks i went to the local shop and they got a guy down there he knows his fiddys everything about them and he told me that a xr70(16mm) would be perfect so i dont kow wat to do i can get a 16mm carb for 30 bucks would it be worth the other 70 for the 20mm he told me that 20mm would be to big?

 

Depends on what you want. 16mm carb will give you better bottem end, 18 will go in between, 20 will give you more top.

 

i think that yeah the 20 would be too big for a 75 kit and esp for a stock head. try the 16 that sounds like a great deal and you won't regret it if ya waste only a little money compared to a lot. i hated the PC20 on my 88 kit so much i sold it and cut my losses, it destroyed my low end torque and increased the throw of the throttle it sucked. but don't get me wrong some people love their big carbs just not me.
B

 

potential has said it right once again, I rock my stock carb on my 88 and love the power for stunting, if your going to ride your bike wide open, then go for a bigger carb, but if you want to ride wheelies for blocks keep it stock

 

i want the bottom end cuz i do alot of really slow wheelies so im gona go with 16mm my bike wont hardly run with the stock it wont go past like 2000rpm before it messes up, u wanan know wat its doin go put ur bike on 3/4 choke and ride down the road thats it

 

it has to be something stupid, not calling you stupid but the stock carb should work the nuts

 

all u people that say the 20 is too big ( no offence to anyone ) just plain and simple cant tune a carb. ive put them things on 72s and 88s and they run flawless. get what u want for the 72. definately dont waste the time with the 16mm. its only 3mm over stock. if u dont have patience and knowledge of tuning a carb, leave it stock.

 

I've got an Xr70 carb sitting here that I was gonna put on my fiddy.. still not sure if I wanna do it

 

nags you wana sell it ????? what exactly do you have??//

 

it's a stock xr70 carb. I eventually wanna use it

 

i was able to tune the pc20 to run strong as hell on the 88, but i just didn't like what it did to the torque curve, it's all preferece i guess.
B

 

How bout a 22mm carb
http://cgi.ebay.com/ebaymotors/ws/eB...category=34284 ?

 

like fab said "you dont know how to set up the carb"
all those carbs will work just set it up right,if anything with a bigger carb you gain bottom end not loose it ,IF its set up right

 

Bigger carb = More top
Smaller Carb = More bottem

 

I spent a few hours playing with my stock carb yesterday. I just put the 88 kit in last sat. and I needed to find tune jetting. It runs clean and strong from idle to W.O.T. I can't see any reason for a bigger carb unless you were running or racing mostly top end.

 

Sounds like your to rich, move the clip up a notch or two. Just follow the throttle cable to the carb, unscrew it. The clip is on the needle. Up for lean, down for rich.

 

everyone has there idea set up
some guys i know run 28 mm flatslides i use a 24 mm roundslide,some use 20mm ,some use 18mm
read up, play with it,try some different things
see which works best for your set up

 

ZYFIDDY, just curious, what type of riding do you do and what size bore,what head,etc. are you running with the 24mm carb. Hows the thing run on low and mid? I'm always interested in how different set up perform.

 

Fab you know how I feel about this but for a 75cc bore kit a 18mm carm is the best ............ period. It can't bog the motor down as easily as a 18 mm carb can.

The only reason I may get a 20mm is becuase they are almost always much cheaper. Another alternative to a 18mm r 20mm carb would be to find a nice used xr70 carb off ebay............

 

I had a 22mm for 30$ on that ebay thing.