# 2007 Brute Force 750 KVF750A Need Help after cleaning carbs



## dwood1354 (Mar 21, 2015)

Greetings Everyone! So far this forum has been awesome so I appreciate everyone's input and interaction.

I have a 2007 KVF750A. It was backfiring and sputtering and running like dog turd after sitting for a couple years.... I know I know...poor thing. I've come to my senses and decided to get back on the horse so I tore down the carbs cleaned them inside and out ( they were pretty gummed up with the green ethanol junk ). 

Now it starts right up when choked. Still backfires occasionally and sputters a little bit, but it absolutely won't run with the choke off. I can feather the throttle but it definitely won't idle and if i hit the throttle hard it dies off.

Clean Carbs, Airbox is on and closed, New Plugs, What do I check next? 

Thanks in advance!!


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## dman66 (Feb 20, 2011)

Did you clean out the gas tank ? If you did, then maybe carbs are still dirty.


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## dwood1354 (Mar 21, 2015)

Nope. But I guess I should have. Just now drained the bowls again and am taking off the tank to do that. Seems to run good when choked but only then. Will report back shortly.


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## dman66 (Feb 20, 2011)

And the air filter and air box were installed when you had the issue ?


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## dwood1354 (Mar 21, 2015)

yes I put the air box on cleaned the filter but the filter back on hooked up all of the lines and also have the lid on tight. I had read on another thread that if it was off it would cause part of the issue


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## REDNEK (Feb 14, 2015)

clean tank and carbs well I have seen fuel turn in to fossil again after a few years I literally dumped chunks of old fuel out of a tank


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## dwood1354 (Mar 21, 2015)

Alright so here is the skinny.

I pulled the tank ( not quite as easy as I had hoped ) Cleaned it out, gas was a pretty deep gold. Dumped all that out. Pulled the pump and pickup tube filter cleaned. Cleaned it out with mineral spirits, blew out the residual. Went down to Carlton and bought some Non-Ethanol premium gas to run in it. Added a Gallon of that back in the tank.


Would not fire w/out the choke. I choked it full and fired right up. Definitely ran a bit smoother. Throttle response is good with choke no backfires.

As soon as I start taking the choke off it starts to struggle. I can throttle it and take the choke off, but it starts backfiring and runs like crud. Throttles right up but I'm pretty sure the neighbors thought I was firing off rounds.

I uploaded a video to youtube
07 Brute force 750 runs horrible without choke - YouTube

:thinking:


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## dman66 (Feb 20, 2011)

I hate to say it, but it sounds like a problem within the carbs. It sounds like the air/fuel pilot screws may not be feeding enough fuel - turn them out to 2 1/2 turns each - if they are already there try 3 turns out each.If that don't help, then more than likely have to pull carbs and reclean them - pulling the pilot jets and reclean them. Are the rubber carb and intake boots good with no cracks to allow air past them ? Also double check to see if the slides are moving when engine is off - move with you fingers, check the slide diaphragms to insure the diaphragms are sealed properly and have the little brass jet installed, check the two rubber lines coming off the left side of the carbs to insure not blocked same with the carb bowl overflow tubes. There is so much more yet, but I'd bet pilot jets are clogged or too much air coming in through the rubber boots.


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## REDNEK (Feb 14, 2015)

and its not in limp mode for sure right no 2wd 4wd flashing or check belt light??? does the machine have stock jetting is there a pipe on it or a snork???


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## dwood1354 (Mar 21, 2015)

I bought it slightly used in 08 And it already had a Big Gun Exhaust. It is a bit more aggressive than stock so I have to assume between those two things it was jetted. I was a bit to nieve to ask back then and to look Last week when I had them out of the carbs. Sounds like I need to tear them down again. I did check the slides and diaphragms looked good. the boots seemed fine when I scrubbed them last so I'll check them again. Maybe I missed some stuff. after pulling the tank and those once already starting to not be so intimidated.


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## dwood1354 (Mar 21, 2015)

Sure enough. Pilot jets were plugged solid. I must have either did a crap job cleaning them or sucked up junk because I didn't clean the tank the first time around. I had to drill out the pilot screw plugs but one was at 2.25 and the other was at 3. Both at 2.5 turns now. Fired up and was able to turn off choke right away. Ran like a screaming pig. thank you thank you. I'll put up a couple pics of drilling out the screw plugs so the next person reading this feels better about doing it

https://drive.google.com/open?id=0B5A6OaCXTB0qRFdYZ2lZM3doRjg&authuser=0

https://drive.google.com/open?id=0B5A6OaCXTB0qa1djbkFzeHY0SWc&authuser=0

https://drive.google.com/open?id=0B5A6OaCXTB0qV21FUF9pcWpVazQ&authuser=0

https://drive.google.com/open?id=0B5A6OaCXTB0qLTdaRmREalZ6Yzg&authuser=0


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## dman66 (Feb 20, 2011)

Awesome.... a lot of us have had this happen before. Glad to hear you can enjoy the Brute now.


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