jjfizzle51 Posted January 22, 2011 Report Share Posted January 22, 2011 Hey guys I know this is the banshee Hq but have noticed that alot of you guys have YFZ450's as well so I am hoping you may have some advice. Anyways my buddie has a 09 YFZ450 with FmF full exhause and K&N filter he has been running stock jetting for like 6 months! What would you recomend he switch his jetting too? We are at about 4500 ft he lacks the know how to tune it as do I and he is considering paying the shop $100 to Jet it! ha ha any help is much appriciated thanks guys! Quote Link to comment Share on other sites More sharing options...
theshee Posted January 22, 2011 Report Share Posted January 22, 2011 170 main, 45 pilot. Quote Link to comment Share on other sites More sharing options...
-Herbie- Posted January 22, 2011 Report Share Posted January 22, 2011 165 main / 50 pilot / 35 leak jet. this might be a little rich for that altitude. If he's willing to spend $100 I would find someone with a dyno & sniffer and they can dyno & jet at the same time to get it spot on and it will be around $100. changing the jets is very easy, i can do it in 15 min. There are youtube videos to show you how. PM me if you need some help. Quote Link to comment Share on other sites More sharing options...
jjfizzle51 Posted January 23, 2011 Author Report Share Posted January 23, 2011 Ok awesome This is a dumb question but is the higher the number the leaner the jet is? Thanks, Any other opinions would be great! Quote Link to comment Share on other sites More sharing options...
cmepasu Posted January 23, 2011 Report Share Posted January 23, 2011 Ok awesome This is a dumb question but is the higher the number the leaner the jet is? Thanks, Any other opinions would be great! the higher the number the richer you will make it. put a 165main 45pilot and 4th clip on the needle and you should be really close. Quote Link to comment Share on other sites More sharing options...
jjfizzle51 Posted January 23, 2011 Author Report Share Posted January 23, 2011 Dumb questions but what is the needle? also any air screw suggestions! Thanks guys I just dont want to tell my buddy something and have it not run right. Quote Link to comment Share on other sites More sharing options...
DallasGDub Posted January 23, 2011 Report Share Posted January 23, 2011 He may not be able to move the needle unless he has a GYTR. I had to upgrade my 08. Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted January 23, 2011 Report Share Posted January 23, 2011 45pilot 170 main,use the dirt bike needle 4th clip its called an NCVQ needle,fuel screw 2.5 out.The needle is a must once you start upping the jets it will run like garbage.Never spray cleaner on the slide take it out 1st b4 you clean and take the rubber off,it expands and will never run rite if it gets fucked up.I have had three come thru my place that people tryed to do there own shit Quote Link to comment Share on other sites More sharing options...
SonOfSand Posted January 23, 2011 Report Share Posted January 23, 2011 There are some crazy numbers being thrown out. With almost identical mods your friend has, I ran 168 main, NVCQ needle on 4th from top, and a 48 pilot at glamis (sea level) for two seasons and the engine ran perfect. I moved to Rexburg ID (5000 feet), and I was way down on power. You need to be around 160-162, needle on 3rd from top, 42-45 pilot. That's where I ended up and it was better. After I built my 450 into a 480 with webs and 12:5:1, I had it dyno tuned locally, I made the most power and had the flattest curve at 155 main, 5th from top... go figure. Quote Link to comment Share on other sites More sharing options...
RadarRacing Posted January 23, 2011 Report Share Posted January 23, 2011 I may be wrong but i believe its a "NCVQ" he needs not a nvcq. These guys are right on yer jetting a 165/168 is needed. might get away with a 160or 162 if it doesnt have the cam mod. But its lean and not as fast as stock with stock jetting even if it feels snappy and fast. Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted January 24, 2011 Report Share Posted January 24, 2011 im at sea level an usually run 170-175 main but have more mods so 168 is close im not sure on the exact lettering of the needle call FAST he stocks them Quote Link to comment Share on other sites More sharing options...
Wheelman Chassis Posted January 24, 2011 Report Share Posted January 24, 2011 i used to run 170 main, but i had a nmotion pipe. u never said if he has a stock filter and if he runs a air box lid, i run oxy fuel now with a ton of other mods so thats all the help i can be . do the cam mod,bore the carb,add a quick shot accel. pump cover,and get a good intake. your buddy will crap himself ..lol jk Quote Link to comment Share on other sites More sharing options...
jjfizzle51 Posted January 25, 2011 Author Report Share Posted January 25, 2011 i used to run 170 main, but i had a nmotion pipe. u never said if he has a stock filter and if he runs a air box lid, i run oxy fuel now with a ton of other mods so thats all the help i can be . do the cam mod,bore the carb,add a quick shot accel. pump cover,and get a good intake. your buddy will crap himself ..lol jk Yes I did I said he had a K&N, If by stock you mean connected to the stock mount then yes it is stock but he cut the whole airbox off so Full FmF Pipe and K&N with airbox removed there is a huge diversity in everyones answers ha ha I'm not sure what to go with... any other suggestions? Thanks for all the help guys you rock! Quote Link to comment Share on other sites More sharing options...
camatv Posted January 25, 2011 Report Share Posted January 25, 2011 if your this lost you might want to just take it to a shop. just make sure the shop KNOWS yfz's and will stand behind their work and make sure you ask them specifically about that.... 4 strokes are kinda tricky to get jetted just right they are more finiky than a 2 stroke. the carb supplies fuel based on the engines PULL on the carb so sometimes to get the right fuel air you need to lean it down.. ( on bigger builds) because the carb is getting much stronger pull through the carb and the carb is pressured up more.. 4 stroke carbs also need to atomize much better due to the ports curves and such and that curve likes to switchthe fuel back to non atomized. and in al reality you will end up between a 160-178 main, and anywhere from a 42-52 pilot it just takes time. i found that on one i did the 170/50 quick shot 3 ( excellent!) worked killer and also doing the pumper link or mod or o-ring worked killer as well. it seemed to me with the quick shot and adjustable leek jet it liked a much bigger slow jet. they all seem to jet a lil differnt and you will really need to know what feels right and or check plugs to get it really close a dyno with a "sniffer" is almost ideal but most bikes i have seen come off the dyno are lean because of the load, airflow, time and hp gaisn that most dyno tunners are looking for. i k now the quick shot 3 seems exspensive ( 100 bucks) but its a very nice addition to tuning and will take the BOOGOGOGOGG out of it once you get it right and as soon as you stab the throttle it jumps into a wheelie instead of BOGOGOGOGO you will be very happy Quote Link to comment Share on other sites More sharing options...
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