Brute Force issues

[2fastlx]

Friend has an 06 brute force 750 that has been giving him problems lately. He says the bike will fluctuate from idling normally to dropping rpms like it will stall, only to return to normal idle rpm again. This happens every 5 seconds or so. He says the bike runs fine after starting cold, but it begins to run like this after becoming warm. The bike will do this at lower rpm while cruising as well, but not under WOT. Any ideas as to what this could be? Thanks in advance.

[Which 450?]

How hard is it to start when its cold? These need the valves adjusted often

[2fastlx]

He says it will start right up but it just runs rough at low rpm. What do you mean by adjusting the valves, and how do we go about doing this? Sorry I am not familiar with this bike at all, its much different than this sportbikes I am used to.

[Which 450?]

if it starts right up its probably not the valves. How many miles are on the bike? has it sat for a long period of time? how new is the gas?

[2fastlx]

Not sure on the miles. He bought the bike about 2 months ago. It ran great after he first got it, until he had a problem with some hi-lifter belt? He took in and they fixed that, and shortly after it started running this way. Bike has not sat, and gas is fresh. I asked if the problem started right after they worked on it, but he said it ran ok for a little while after the belt repair.

[Which 450?]

Yes the only belt to use is oem. But it really sounds to me like he needs to get into it and check out the carbs, maybe while he has it apart, check the valves.

[2fastlx]

ok thanks for the info. Having never messed with this bike, how would we go about adjusting the mixture? Are the screws easily accessible? Thanks alot for the insight.