The Best Carb Money Can Buy? | SmartCarb SC2

[Music] this carburetor has no jets automatically compensates for altitude and temperature changes makes more power than a stock carburetor all while being more economical and looking absolutely stunning in the process isn't that exactly what your bike is missing well like all good things there are a few caveats we live in a world with smartphones smart watches smart tvs and even smart speakers computer is it a good day to ride every day is a good day to ride so it's definitely time that we had smart carbs right well of course you could argue that that's exactly what electronic fuel injection is but smart carb the company disagreed and created this the smart carb sc2 full disclosure smart carb sent me this carburetor for my yamaha yza 250 for free so that i could test it out and share my thoughts with you guys in this video however i am free to tell you that it's complete rubbish if it actually is now there is a lot to cover on this one so instead of boring you with a never-ending monologue spitting facts and figures at you kind of like this i decided to compile a list of questions that i would expect any good biker to ask me about the carb had i actually consulted you that is about as many as are currently in your garage because it's easily a one-man operation it was much faster and easier than i expected and really didn't require the procrastination that i gave it [Music] once you've enjoyed the beautiful unboxing experience you first have to remove your stock carb i also removed the subframe to get better access and since the air boot will need modifying in any case and all you need to be left with is the bare throttle cable the new cap spring and slide can then be installed onto the throttle cable and tightened up if your reed intake boot has any alignment tabs like my yz did you will need to first trim them off so that the carb can sit flush it's important to ensure that the slide has its full range of motion otherwise you can adjust the throttle cable slack on top of the carb or at the throttle itself the cable is then very close to the frame since the smart cob is both taller and wider than the stock cob but it doesn't hinder the movement of the cable in any way and then the throttle position sensor can be plugged in while the other cable is left blank the rear of the carb has a vent scoop that needs to be opened to function however the yz has a lip in its air boot that would block this so it needs to be trimmed not all bikes would need trimming but it's just the top bit that needs to go i may have gone a bit overboard with it but i didn't want it to be blocked at all so with the subframe back on and the air boot tightened up i could give it some fuel the fuel line was now a tiny bit short but thankfully the included fuel filter made up the difference unfortunately i didn't fix the direction of the filter quickly enough to avoid rude youtube comments the larger co-op does leave the air boot very close to the rear shock however smart cobb have addressed this and say it only touches at full swing arm extension and shouldn't wear through it [Music] you don't just because a kehin or even electron carb need to look like this doesn't mean all carbs need to and that is what makes the sc2 so good looking alongside its beautiful machining that is all it has is one hose to the fuel tank and one drain hose in case you need to drain the float bowl there's also a choke on the correct side an idle set screw and a clicker adjuster on the top this clean design is possible because it's all internally vented which is brilliant because it means there is never any fuel spillage you can lean your bike over like this to wash underneath it or if there are no trees around to lean your bike against without fuel pouring all over the floor in a word magic but in reality it uses the design invented by a chap called william edmondson it's kind of the same concept as used by electron carbs but with smart carbs own unique improvements [Music] instead of a needle the carb has a metering rod which is flat on the side that faces the engine and curved on the intake side so as air rushes past the metering rod there is an area of low pressure created on the flat side of the rod that ultimately pulls fuel up from the float pole this is also how it compensates for altitude changes because obviously the higher the altitude the less air there is therefore there is a weaker signal on the metering rod bringing up less fuel from the float bowl creating the perfect mixture and since fuel can rise so high up the metering rod thanks to this effect it increases atomization of the fuel meaning it burns cleaner makes more power all while being more economical obviously there is a lot more to it than this but this is the basic principle of how it functions without jets and how it compensates for altitude changes not even all you need is your favorite local track or trails and then you have two knobs at your disposal the idle screw works like a regular carb raising or lowering the slide to let more or less fuel into the engine but the metering rod can be raised or lowered with the clicker adjustment on the top of the cob which exposes more or less of the tapered rod and opening or closing the gap where fuel exits the float bowl so you can tune your bike while you ride with just your fingers no tools required to change the metering rod height you just kill the engine pin the throttle and press down the clicker adjuster which slots an allen key into the top of the slide then with the clicker depressed you can turn it which changes the rod height left for leaner and right for richer so when you order your card they request information like what fuel and pre-mix ratio you use as well as what engine modifications you've done to your bike so that they can then set the baseline settings on the card to give you a good starting point before it's even shipped to you i've seen people's bikes start right up and run perfectly out of the box however mine started first kick after my install but wouldn't idle and had very low power down low which in my ignorance i assumed meant it was too lean and needed more fuel to make more power i should probably mention that i've never actually tried to tune a car before but luckily the manual was very good at explaining what i needed to do to get my new car to run correctly but it wasn't quite as useful as having direct help from someone that works at smartcob so luckily nathan was more than happy to message me back and forth to help me understand how my new carp works now this isn't special treatment because i'm making a video about this i've seen plenty of people on forums talking about getting help from nathan or other people at smart cop it was a little bit tricky with the time difference from here to america but it did make my life a lot easier so this is how my tuning experience went down [Music] first it wouldn't idle and had low power down low so i went four clicks richer because in my mind more fuel meant more power but this didn't work [Music] nathan then told me that they shipped the carbs on the richer side to prevent engine damage so i should go leaner until my revs start to pick up turns out i was going in the wrong direction but nevertheless i do appreciate that they ship them on the richer side to protect my engine [Music] 36 clicks later my bike would idle and run brilliantly throughout the rev range however i wasn't sure if 36 clicks was on the excessive side so i went in search of some advice according to my new best friend nathan 36 clicks was above average however they didn't have any experience with my local fields after all i don't think they've ever shipped one to south africa so i followed his advice and went a few clicks richer while compensating with the idle set screw for the bottom end because the metering rod adjustments affect the entire power curve so better to be richer up top to be safe well that's exactly what i did on day two i thought i was making it better messing around with any adjustment i could find but it's not a problem in fact i think they kind of expect you to do that because they put all the original settings on the back of the manual so you can revert your slide height and metering rod height back to the starting point if need be however if the bottom end is perfect but the top end isn't quite right that is when you'd swap out the metering rod for one with a slightly different taper that is just a circlip removal away and although this process is only required during the initial setup of the cob i still couldn't imagine having to open up the carb and remove the slide every time i wanted to make a little metering rod adjustment like you do on electron especially at a dusty track i couldn't have opened my carb 18 times to make two click adjustments at a time just to get to the 36 clicks that i needed i thought so too but their website guides you through the process first you tell it what bike you have and it tells you what size carb you will need like i needed the 38 millimeter then you can choose whether you want the tps or not and customize your float ball color to match your bike if you fancy and lastly you provide your engine modifications and fuel info and that's it honestly nothing i wasn't interested in the sc2 because the stock car was bad i'm just intrigued by the technology and innovation of a very old part i always thought my bike was running a tad rich but because it was running nicely i didn't want to mess with it in case i made it worse jets are greek to me but the sd2 makes learning and changing settings much easier i also like the idea that i could leave my house in johannesburg at 1600 meters above sea level and go ride a track in cape town down at sea level without having to change jets or figure jets out that's how life has always been for me riding fuel injected bikes so it's kind of a first world expectation [Music] yes but with the sc2 it kills the planet slightly less its incredible fuel atomization enables it to burn 25 to 30 percent less fuel than the stock carb while making eight to 14 percent more power as for the power my butter meter isn't sensitive enough or talented enough to really notice but i definitely used less fuel in fact i could just make out the fuel level in the tank after a morning at the track whereas normally i wouldn't even catch a glimpse of it and need to top it up quite a bit honestly there's no catch it just depends on whether it works for you or not if you change altitude frequently or even within a ride you'll love it if you want your bike to look better and you can afford it you'll love it if you're just intrigued by the innovation like i am you'll love it if you're racing and looking for marginal gains you will love it and even if you're just sick of stripping phillips screws you'll love it but chances are if none of these things define you then you're probably going to be better off with your stock carb anyway but anyway i hope that this video can give you some more information about smart carbs and possibly even help you make your mind up if it did please hit the like button let me know what you think about smart carbs or share your experience with them down in the comments and i'll see you on the next ride

Channel: Chaos Causes

Views: 2,662,396

Keywords: chaos causes, The Best Carb Money Can Buy?, is this carburettor better than fuel injection, smartcarb sc2, carburettor, carburetor, lectron carb, billetron, h series, fuel injection, efi, tpi, dirt bike, jetting

Id: tBuwSkjruk0

Length: 13min 25sec (805 seconds)

Published: Fri Dec 03 2021