# 2005 750i brute force w/ miss



## holbrook05750i (Jul 11, 2013)

i just got a 750 brute force (7-9-13) its got 26xx miles one it with 2xx hours... its got a k&n filter, dynatek cdi, and a hmf slip on.... i traded for it and i knew it had a miss in it, its been there since the exhaust was put on... so i pretty sure it needs rejetted, jet kit is on the way... i'm wanting to know what do i need to set my jets to? elevation around 1500'-2000'... its backfireing really bad and cutting out... i still have most of my power.... do you think that a jet kit will fix my problem?


----------



## holbrook05750i (Jul 11, 2013)

Ok I cleaned the Carb and its running alot better but now has a small miss at low throttle and popping/backfiring in the exhaust at idle and decel... also it had the number 155 on the middle jet in the front carb, and 150 on the middle in the rear... I think i'm lean and i've read the rear should be bigger will this cause the popping/backfiring and small miss at little throttle? Do I need bigger jets?


----------



## dman66 (Feb 20, 2011)

Need more info for your exhaust system and other mods that are done to your quad. The front main jet should be the smaller jet,and the rear main jet is the larger size. The stock pilot/air fuel screws are # 38 - go up to # 40 pilots on each carb,and adjust each to 2 1/2 turns out.Stock OEM needles are marked as NKKL needles - install 1 # 4 shimm under each needle. The main jets are stock sizes of 152 front and 158 rear, but you may need to go up two sizes on each main jet depending on your mods. There is also a lot more to these carbs which is posted all over this site - just read up on the snorkeling/jetting threads.


----------



## holbrook05750i (Jul 11, 2013)

Thanks for the input sorry i've been working.. all mods was done before I got the bike so I know real sure on what all is done I know the pipe is a hmf, k&n air filter, dynatek box under seat that had 3 plug on it I assume it's a cdi, now the Carb has 150f DJ and 155r DJ, DJ springs and needles set at 4th notch with 2 DJ shims/washers on them a/f screw is at 2 turns out I think it has 40 pilot jets b/c the screw out jet beside the main has a star and 40 on theam.. I put 155f 160r and it ran great but had a miss upto 1/4 throttle with a pop on decle so I soft seated a/f screw then brought out 2 1/2 full turns ran like **** with miss all the way though with popping backfiring now I'm at 2 turns just like DJ kit said... Can you help me from here?


----------



## FABMAN (Dec 18, 2008)

do you have a vacuum leak?


----------



## holbrook05750i (Jul 11, 2013)

I know it sounds dumb where is the vacuum lines? All I've seen is two different sets of over Flows one on two on top two on bottom


----------



## FABMAN (Dec 18, 2008)

I wasn't necessarily referring to the vacuum lines for the fuel pump, but maybe the carburetor boots to the head, the choke cables have o-rings on them they could leak, and the vacuum diaphragms can leak as well.


----------



## holbrook05750i (Jul 11, 2013)

oh ok i didnt know for sure this is my first kawie... i checked boots, diaphragm all checked out good... i cant understand it was running good when i first put the 155f and 160r in will a lil miss and pop and all i did was adjust a/f screw and now its screwed... i have tried ever setting from 1/2 to 4 turns out never could find it... then i started w/ jet sizes and needle setting every thing... i think its the needles b/c i got a good idle and no miss till around 1/4 throttle and runs good from 3/4 to wot... all i have is the dj needles and springs..


----------



## dman66 (Feb 20, 2011)

There are a lot of reports about DJ needles bouncing around inside the carbs causing poor mid range from the carbs. In this case you would order the NFKL needles for KAWASAKI PARTS site or pjmotorsports,and install one each into each carb and install shims under each needle as needed which usually one to two # 4 brass washers under each needle is enough.


----------



## holbrook05750i (Jul 11, 2013)

Where's the cheapest place I found them for around $18 each.. Could I modify the plastic thing the spring sits on and put more presser to stop the DJ needles from moving?


----------



## mikenick937 (Mar 4, 2013)

What's the needles your supposed to use, NFKL or NKKL?? NFKL isn't it. I have those in each carb. I never did get rid of all my hesitation.


----------

