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Discussion Starter #1 (Edited)
Carb set-up for a brute 750

Hey everybody just tryin to get a lil' insight on a carb set-up for a brute force 750 from anyone around the nc area, i have a 2006 brute force 750 again just tryin to see whats workin for fellow brute 750 riders in nc.

A little info about mine hmf slip-on, K&N in the airbox, 150 in the front carb & a 155 in the rear, needles on the 4th notch, a/f ratio screws out 1 1/2 rounds,& snorkeled. future plans: a dynotek cdi box, ,outerwears pre-filter, stereo, 2" hl lift kit, & 29.5" outlaws
 

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Thats awful high jets for the snorkels. Your needles are fine...air screw needs to be about 2-2.5 out and I would run try a 138f & 142r. Is it running good right now? If it is just leave it.
 

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Here you go buddy..... Official jetting thread! :rockn:
 

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Ha....Thanks. If anyone has any problems with jetting please post them here and I will try to answer them as quick as I can. Sometimes it hard for me over the web or phone with out riding the bike....but I will try to help as much as possible.
 

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Discussion Starter #5
It's sputtering a lil' bit from closed throttle to around an 1/8th open & it's also bustin out @ 55 on the speedo i'm runnin 27" outlaws right now but, i thought i would see more than 55 even with the 27" outlaws.
 

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It's sputtering a lil' bit from closed throttle to around an 1/8th open & it's also bustin out @ 55 on the speedo i'm runnin 27" outlaws right now but, i thought i would see more than 55 even with the 27" outlaws.
What kinda clutching do you have ? You can't trust the speedo with 27's either...you could be running 50, 60, or even 65...lol. really! They aren't too reliable for correct speed.
 

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Bootlegger,
I went to 2 turns out on the a/f screws and it got worse. I think I'm gonna go back to 2 1/2 for now unless you have any other ideas. I know it's hard to come up with answers if you're not hearing the bike.
 

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Just got the muzzy and Dyno Jet Kit installed last night and everythign back together.
She fired right up great but i have two questions.

I have to set the manual idle adjustor screw to a pretty high idle for it to be a smooth idle, what do i need to change in the carb to be able to have a smooth idle without the bike sounding like i have to have it revving heavy to be a smooth sound?

It seemed to run fine on a few stop to full throttle runs except when i let off the gas and coast to a stop it pops out of the exhaust, what do i change and in what direction to correct this?


Shoudl i try to get the idle set correct first then work on the pop as i here you should only change one thing at a time when doing your own carb work?

Right now i am at 653 feet above sea level, muzzy exhaust, dyno box CDI, dyna jet kit with 150 front 155 rear, needle on 4th clip down with two washers on top, 2 turns out on the A/F screw

Also do u mirror every change in front and back carb? or do u have to adjust each carb to there own settings?

thanks
 

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i need bootleggers help. I have a 650i brute running well. it has a hmf pipe and snorks . my front jet is 142 or 140 and my rear is 148. now is pops and backfires everytime i let off the trottle. now im elevated under 3000 feet. my nettle is set at 3rd notch. i had it on 4th but it ran bad...... im reay to put stock nettles back in and factory my air screw back to were it was and just use dyno jets as main jets. im tired of the back fire. and i do not have a exhaust leak either. plz help , oh and sometimes wen im full out, you'll hear one cylinder off timing with the other one. this only happends in 24 degrees celcius + , wen its cold out it runs awsome. i think my jetting is still high?. plz let me knoow what u think , im fed up with jetting. my quad ran wayyy better without snorks. and i want the power back...
 

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Just got the muzzy and Dyno Jet Kit installed last night and everythign back together.
She fired right up great but i have two questions.

I have to set the manual idle adjustor screw to a pretty high idle for it to be a smooth idle, what do i need to change in the carb to be able to have a smooth idle without the bike sounding like i have to have it revving heavy to be a smooth sound?

It seemed to run fine on a few stop to full throttle runs except when i let off the gas and coast to a stop it pops out of the exhaust, what do i change and in what direction to correct this?


Shoudl i try to get the idle set correct first then work on the pop as i here you should only change one thing at a time when doing your own carb work?

Right now i am at 653 feet above sea level, muzzy exhaust, dyno box CDI, dyna jet kit with 150 front 155 rear, needle on 4th clip down with two washers on top, 2 turns out on the A/F screw

Also do u mirror every change in front and back carb? or do u have to adjust each carb to there own settings?

thanks
For your idle. Turn your screw out to 2.5 turns and that should fix it....maybe 2.75 turns. If you can make you a tiny short flat head you won't have to pull the carbs off. After you get that fixed see how it runs and let me know.

Your Dynotek CDI will sometime cause a tiny misfire cause of the advance timing that you can't get rid of...but its a small one that is not very noticeable. You might wanna try a 148 & 150 and see if that helps or makes your backfire worse. Its hard for me to tell with out being there...but that is what I would try.
 

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i need bootleggers help. I have a 650i brute running well. it has a hmf pipe and snorks . my front jet is 142 or 140 and my rear is 148. now is pops and backfires everytime i let off the trottle. now im elevated under 3000 feet. my nettle is set at 3rd notch. i had it on 4th but it ran bad...... im reay to put stock nettles back in and factory my air screw back to were it was and just use dyno jets as main jets. im tired of the back fire. and i do not have a exhaust leak either. plz help , oh and sometimes wen im full out, you'll hear one cylinder off timing with the other one. this only happends in 24 degrees celcius + , wen its cold out it runs awsome. i think my jetting is still high?. plz let me knoow what u think , im fed up with jetting. my quad ran wayyy better without snorks. and i want the power back...

I understand that fully. Where do you live? I assume not close to Tennessee right?...lol. One thing is your jets seem to be too far apart on sizes. Most everyone will be for example 140 & 142 or 140 & 144. Sounds like on cylinder is getting too much or not enough. Try a 144 & 148 and keep them that close or closer. I understand how frustrating it can be....I have jetted a few that I had to try almost every combo in the kit...lol. Put your air/fuel screws at 2.5 turns out. If the 144 & 148 is worse try going to a 140 & 142...have you tried those yet? Sometime but its rear that a 650I don't like Dynojets needles...but its mainly on the SRA models you see that issue. If you went to the 3rd notch and it got better your bike was too rich at 1/4-3/4 throttle positions.
 

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no i havent got it at 140 and 142, i was hoping to try 138 and 142 like you said in your previous post and i live in canada,ontario, sudbury. its always good to help a fella neighbour out tho:) the lowest i wen is 142 148. Quick question . wen i turn my snorkel twords the front to get "Ram Air" i go faster by 10 km/h. can it be that im to rich wen the snorkel is facing me and 138 142 will help alot better. thanks for the help :)
 

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no i havent got it at 140 and 142, i was hoping to try 138 and 142 like you said in your previous post and i live in canada,ontario, sudbury. its always good to help a fella neighbour out tho:) the lowest i wen is 142 148. Quick question . wen i turn my snorkel twords the front to get "Ram Air" i go faster by 10 km/h. can it be that im to rich wen the snorkel is facing me and 138 142 will help alot better. thanks for the help :)
It very well could...the 138 & 142.Also put your needles about on the 4th notch from the top and try the 138 & 142 and 2.5 turns on your air screws....
 

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i have another question. i have hmf swamp serie XL pipe and is it normal for it to back fire on deacceleration? and 4 th notch isent that rich in the mid range? is that want i want?:rockn:
 

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i have another question. i have hmf swamp serie XL pipe and is it normal for it to back fire on deacceleration? and 4 th notch isent that rich in the mid range? is that want i want?:rockn:
That is what you wanna start with...it you leave in on the 3rd and drop down on jets it may be too lean.
 

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Hey Bootlegger, in need of some help again. I have a 2006 650 SRA with 2 in snorks, and i will be doing the exhaust mod in time. Since i installed the snorks it seams to be getting too much fuel. It smells like gas out the exhaust and doesn't like to start. I have the wheeler apart and the Dynojet kit just arrived. Could you give me some advice on where to go from here?
 

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Hey Bootlegger, in need of some help again. I have a 2006 650 SRA with 2 in snorks, and i will be doing the exhaust mod in time. Since i installed the snorks it seams to be getting too much fuel. It smells like gas out the exhaust and doesn't like to start. I have the wheeler apart and the Dynojet kit just arrived. Could you give me some advice on where to go from here?
Looks and see what size your stock jets are....I can't remember and let me know.
 

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usually stock jets are 155 mains in both cylinders. okay and thanks bootlegger. i will try your setup. but how will i know if im too rich or lean at WOT or in the mid range or at idle?
 

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usually stock jets are 155 mains in both cylinders. okay and thanks bootlegger. i will try your setup. but how will i know if im too rich or lean at WOT or in the mid range or at idle?
Let me know how its running. if its too rich it will fall on its face and not have much power. Just let me know how it runs and we will got from there.
 

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Hey Bootlegger, in need of some help again. I have a 2006 650 SRA with 2 in snorks, and i will be doing the exhaust mod in time. Since i installed the snorks it seams to be getting too much fuel. It smells like gas out the exhaust and doesn't like to start. I have the wheeler apart and the Dynojet kit just arrived. Could you give me some advice on where to go from here?
If your stock jetts are both 155's put the needle on the clip the directions say and put your air screw there as well....but put a 138 & 140 Dynojets in it. and start from there. That is one size smaller than your stock jets. The number are different on the dynojets. Let me know.
 
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