carb sizing

[sootman73]

So not knowing what has been done to the engine in my banshee i was wondering how big of main jets were too big for the stock size carb. Right now im running 290and i might go to 300 or 310 because its still lean. should i be looking to get bigger carbs like 28's? i dunno how or if you can tell what carbs should be on it without pulling the motor apart and figuring out what all has been done to it?

[bansheesandrider]

So not knowing what has been done to the engine in my banshee i was wondering how big of main jets were too big for the stock size carb. Right now im running 290and i might go to 300 or 310 because its still lean. should i be looking to get bigger carbs like 28's? i dunno how or if you can tell what carbs should be on it without pulling the motor apart and figuring out what all has been done to it?

You need to jet it for the amount of air going through the engine. A small carb will limit the amount of air but you can still jet it correctly for the amount of air that is actually flowing. Do you still have stock reed cages? What kind of pipes? Take the reed cages and/or the pipes off and look at the ports, are they stock or are they ground on(ported)? Stock carbs are great for better throttle response and low end power. They will work just fine on motors that are stock stroke, and for a little gain they can be bored to 27.5mm. That way all the stock jets and parts still fit. Going to bigger carbs will reduce your throttle response and low end power and will give you more RPM and top end power, assuming you have the other mods to support a biiger set of carbs.

Some people on here have had good luck with the OKO knock offs of Keihen carbs and some people have had problems with them, I say you get what you pay for. That being said, I would just bore out your stock carbs (mine cost $35 per carb to do) and then get it properly jetted. That way you won't need a new cable and you can still get parts at any Yamaha dealer (they will stock parts for stock carbs, but will have to special order parts for aftermarket carbs).

[coryv4]

So not knowing what has been done to the engine in my banshee i was wondering how big of main jets were too big for the stock size carb. Right now im running 290and i might go to 300 or 310 because its still lean. should i be looking to get bigger carbs like 28's? i dunno how or if you can tell what carbs should be on it without pulling the motor apart and figuring out what all has been done to it?

i am running 400s in my stock carbs

[SheeManWomenHater]

interested in selling your +6? let me know. or i'll trade you my stock swing arm for it. as long as its not a stock modded to +6

Edited August 5, 2011 by SheeManWomenHater

[sootman73]

okay i wasn't sure if it got to a point that it made sense to step up, i have no idea if my reeds are stock because i dont know what stock ones look like compared to afttermarket. i have had them out to be cleaned after badlands so i know what the ones in it look like. and i have t5 pipes on it.

 

supposedly it is bored out to 410cc but i dunno if thats even possible. oh and some bottom end work. thats all the kid knew and his dad was too stupid to tell me what he did to it..... yes. pain in the ass.

[camatv]

just put bigger jets in it till it slows down.