2008 Brute Force 650 running good going forwards runs good going backwards and except when bog down and stuck going forwards sounds good but when put in Reverse when bog down in the mud and gives it a lot of throttle it starts spitting sputtering and backfiring what could be causing this

Marvin

• 85242 Answers
• Posted on Jul 06, 2012

SOURCE: stalls in drive, runs grear in reverse

Engine stalling and rough run issue at low speeds

This problem is commonly caused by a dirty automatic idle speed control valve and throttle valve. Buy a can of throttle valve cleaner (do not use carburetor spray cleaner!) from NAPA or Carquest (made by CRC chemicals) and spray it into the air intake while the engine is running, use up about 1/2 the can, engine will try to stall hold the speed up, shut it down and let it soak for 30 minutes, restart and blow out the remaining fluid, shut it down and disconnect the negative battery cable for 5 Min's to reset the base idle control

Jeffrey James

• 13 Answers
• Posted on Nov 06, 2012

SOURCE: 2010 kawaski brute force atv spitting and sputtering

spray some carb&choke cleaner in the intake while revving it up. if it smooths out then it is a fuel problem. if not most likely in the ignition system (spark plug, wires, or ignition coil) judging by the fact that it idles fine it sound like a coil. ( this next section risks you getting shocked but you wont be harmed, mostly just surprised and a little pain.. ouch) listen for a distinct click sound of a spark. if you can hear this follow the sound and look for the spark. you can also spray the wires with water to see if they will "leak" voltage from the insulation. you can disconnect the coil wire from the coil and hold it close to the coil where the coil wire attaches to the coil and start the engine. with it idling you should be able to pull the coil wire away about a quarter of an inch or more and see a bright blue spark. if the spark is red than the coil is weak. while doing this test hold the wire close to the coil but far enough that you can see the spark and rev the engine like you would when it would sputter. if the spark seems to stop occasionally or gets dim and red then replace the coil. if none of these things happens then reconnect the coil wire and check all cylinders with this test.