# 05 brute back fire in carb



## brutequebec (Jul 13, 2012)

Hi everyone! Im french but ill do my best here  Just bought a 05 BF 750 whit no mods on it. It's been doing back fire from the carb closer to the seat and the exhaust. Plugs were black. Need to use the choke to get it started but would idle fine. I changed the spark plug, readjust the valve, clean air filter but still the same. Im getting my exhaust fix right now wich will probly fix the back fire at the exhaust but what should i do for the carb?? I check the boot and good to go. I tried to run it whitout the fuel cap just to check but no change. Any idea how to fix the carb back fire? The screw are 2 1/2 turn, should i tight them up a little...both or just the one from the carb that do bf?? sorry for all the question but i just wanna fix it asap  Thanks for the help, can wait to ride it the way it supposed to be!!!!


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## dman66 (Feb 20, 2011)

Check choke plungers in each carb to insure they're not hanging up.Check your jets in each carberator and check to see if they are cloged -main jets ,pilot jets,do a carb cleaning while your at it.Check fuel pump to see if getting enough fuel - check strainer on fuel pump inside of gas tank.......


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## No_Substitue_For_A_Brute (May 4, 2011)

dman66 said:


> Check choke plungers in each carb to insure they're not hanging up.Check your jets in each carberator and check to see if they are cloged -main jets ,pilot jets,do a carb cleaning while your at it.Check fuel pump to see if getting enough fuel - check strainer on fuel pump inside of gas tank.......


All good points. Don't forget to check the carburetor vent lines also
for any blockages.
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## brutequebec (Jul 13, 2012)

Even know im too rich?


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## cookgio (May 1, 2012)

Rejet it. To stock jets if it is stock,no mods


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## dman66 (Feb 20, 2011)

If your plugs are black,your running rich on one or both carbs of the idle,mid range,or even wot circuits.you need to take off the carbs,recheck all 4 carb boots,open up the carbs and insure they are clean,insure the slides move,make sure the slide diaphrams are good - don't forget the brass orfices in each diaphram,make sure needles and needle retainers are seated properly,check your choke plungers and check and record jet sizes - then post back.A stock 750 will have #38 pilot jets,#152 front main jet/#158 rear jet,NFKK needle in front carb/NFKL in rear,or ideal would be 2 NFKL NEEDLES - ALL keihin jets.....Have you adjusted your valves yet at 100 hours use.......


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## brutequebec (Jul 13, 2012)

Thanks for all the info!! Ill check tomorow and see how it goes!! I just reajust the valve. I got some new needle, just gotta check wich one i received. Dealer told me the were the same in both carb... Ill post back tomorow when done!!


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## brutequebec (Jul 13, 2012)

So i check everything and found out that one of the boot is crak... Ill get new one see if that fix the prob!


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## No_Substitue_For_A_Brute (May 4, 2011)

brutequebec said:


> So i check everything and found out that one of the boot is crak... Ill get new one see if that fix the prob!


Sounds like you probably found the issue as that will certainly cause the problem you are having.

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