# telling if Brute is running lean?



## camobruteforce (Jul 17, 2010)

how can I tell if my 08 brute 650 SRA is running lean? How can I adjust the carbs if it is running lean to richen is some? the bike idles fine now and has plenty of power, someone suggested that could be a reason its getting hot


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## NMKawierider (Apr 11, 2009)

camobruteforce said:


> how can I tell if my 08 brute 650 SRA is running lean? How can I adjust the carbs if it is running lean to richen is some? the bike idles fine now and has plenty of power, someone suggested that could be a reason its getting hot


If the plugs are burning light tan to light gray, its fine. If they are whiteish its probably lean. Of course if its on the dark side..its rich. You can increase the low end by the a/f screw but know that it will idle rich. The 650s already come with #40 pilots so that shouldn't be necessary.

From midrange...about 1600 and up the CV needle can be shimmed for just a little bit but if it needs more then about a half a jet size, you will have to re-jet the mains.


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## camobruteforce (Jul 17, 2010)

my front plug is a little dark and my rear plug seems to be a light grey color. So I am thinking I may need to lean the front out a bit and maybe richen the back one since the back carb does pop some at low speed/ very low throttle? Where is the air/ fuel screw on the 650 SRA


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## rmax (Nov 21, 2009)

you need to be running at a high rpm then hit the kill switch to shut it off while at high rpm to get a proper read on the plugs , if you return to idle then kill it you could get false reading on plug colors, another way is to get a red lumber marker an clean a spot about 1in out on header pipe, run at steady rpm an mark the pipe the red mark will turn white when heated if one turn faster it mean its running hotter(or lean), just a thought, we did this on our piston aircraft engines to find dead cylinders


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## Bootlegger (Dec 18, 2008)

If its lean you will just have to re jet it. The 650 SRA are one of the hardest to jet though.


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## eagleeye76 (May 7, 2010)

Bootlegger said:


> If its lean you will just have to re jet it. The 650 SRA are one of the hardest to jet though.


 Is this also true with the 650i. Also what's the differance?


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