willardwright59 Posted January 19, 2012 Report Share Posted January 19, 2012 I always get asked what does bigger carbs do for my banshee, really, i wonder the same, what does a bigger set of carbs do for a banshee? Quote Link to comment Share on other sites More sharing options...
blast off Posted January 19, 2012 Report Share Posted January 19, 2012 bigger carbs - more fuel, more air = more power Quote Link to comment Share on other sites More sharing options...
ticktock Posted January 19, 2012 Report Share Posted January 19, 2012 How much is too much? How big can you go on a stocker with pipes? At what point do you go to 34/35? The engine is only going to handle so much fuel/air. This is restricted by a number of things. Bore, pipes, but stroke shouldn't change how much fuel is atomized-right? Great question! Adam Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted January 19, 2012 Report Share Posted January 19, 2012 How much is too much? How big can you go on a stocker with pipes? At what point do you go to 34/35? The engine is only going to handle so much fuel/air. This is restricted by a number of things. Bore, pipes, but stroke shouldn't change how much fuel is atomized-right? Great question! Adam Think about it, when a motor is stroked, (i.e., larger crank shaft throw, stk is 54mm, typical upgrades are +4, +7 and +10mm), the pistons will sink deeper into the cylinders thereby drawing in more air/fuel. So, yes stoking any motor is going to increase displacement much more than boring and it will need bigger carbs to feed it. Quote Link to comment Share on other sites More sharing options...
ticktock Posted January 19, 2012 Report Share Posted January 19, 2012 Think about it, when a motor is stroked, (i.e., larger crank shaft throw, stk is 54mm, typical upgrades are +4, +7 and +10mm), the pistons will sink deeper into the cylinders thereby drawing in more air/fuel. So, yes stoking any motor is going to increase displacement much more than boring and it will need bigger carbs to feed it. Ok, I guess I didn't think about the pistons traveling a longer route. I was thinking the ports are only going to allow fuel in the chamber while the piston is above the exhaust ports. Otherwise the bulk of the fuel would travel out the exhaust. I thought the piston was offset to cure that problem. In truth I guess I don't know about stroked motors but it seemed logical. I will have to research that more to understand how striking works exactually TEK engines are different and only spray while the piston is above the exhaust ports making it more efficient for fuel atomization in the chamber. Adam Quote Link to comment Share on other sites More sharing options...
Surfrjag Posted January 19, 2012 Report Share Posted January 19, 2012 with larger carbs you can loose bottom end power because you essentially loose the velocity from air coming into the motor. not that you cant run the bigger carbs just that it may not be best suited to your riding. i personally wouldnt go with 34/35 's unless i was running a dune ported and or stroked motor and was mainly riding open feilds or dunes. i think a lot of people would be surprised how much power you can get using stock 26mm carbs i tihnk in dyno room ther is one bike with 75hp and running stock carbs and lots of bottom end power and perfect for a all around bike. i am running 28pwk's and i have plenty of topend power for trail riding and the occasional drag race. i also notice when guys run the bigger carbs they have to use large pilot and main jets to make up for the loss of velocity to pull the fuel. with carbs... bigger isnt better. my opinion of course Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted January 20, 2012 Report Share Posted January 20, 2012 Stock carbs will out flow a stock port motor with pipes. Unless you're going with some port work, better reeds and intake, there is not much reason to change carbs. When you go with a bigger stroke motor, there comes a need for more air and fuel which id accomplished with bigger carbs. Also, bigger stroke motors pull fuel more efficiently from the carbs. That's why you might see a 4mm Cub motor run the same jetting as a 10mm Cub motor. Quote Link to comment Share on other sites More sharing options...
willardwright59 Posted January 20, 2012 Author Report Share Posted January 20, 2012 Ok, well heres the situation, this being a play banshee, for some fun around the house and maby some trails this is my current mods: vf3 reeds, coolhead with 21cc domes, timing plate set to +4, pro circuit pipes, wiseco pro lite pistons, k&n pods, hinson dirt digger clutch, billit water impeller, and stock carbs. Opinions on carb size? Most will say 26mm. But i have a great deal on some 28's locally and really want to snag them up! But i want opinions first Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted January 20, 2012 Report Share Posted January 20, 2012 No reason to go bigger with those mods. The stock 26mm carbs will be more than enough to support your mods. Eventually, you will probably want to go with a 4mm motor or at least some port work. At that time, I would determine what carbs are best for the setup. Until then, I'd save your money. Quote Link to comment Share on other sites More sharing options...
willardwright59 Posted January 20, 2012 Author Report Share Posted January 20, 2012 Man, i just cant see doing anouther 4 mill build, but idk, ill get a good price and do it all right and have 2 badass banshees! Maby sell my yz 250. And do the build with that money. Quote Link to comment Share on other sites More sharing options...
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