05 Brute Force Backfire

[robsibe]

Help. My 05 Brute force 750 backfires when you let off the throttle at high RPM's. It is completly stock but has recently been rebuilt. Carbs are clean and I don't think there are any air leaks. Anybody have any suggestions on what it could be? Maybe the jets? What size should I go to? Thanks

 

[munhoez]

What kinds of mods have u put on?

 

[AreWeThereYet]

Check for an exhaust leak on one of your cylinders

 

[robsibe]

This quad has no mods. it is completly stock motor, filter and exhaust. I forgot to mention that it is also hard to get started. You have to crank and crank and it will finally fire. It spits and sputters until it warms up then runs fine except the backfire.

 

[munhoez]

slightly plugged pilots buddy.

 

[KVF 700]

valves need adjusting... have a 2006 kvf 700 with 7800km and have had to set the vavles 4 times, and those sound like the exact same symtoms as mine when valves need to be set. even though the starter is working perfectly fine, i find it starts eaier using the recoil backup when the valves are out of whack.

 

[hadster]

That's normal as far as i know, i had a stock 2008 750 EFI brute that did the same thing, and also new others with the same problem. Fuel injection or carbs, for some reason they like to backfire on deceleration (maybe to wake you up, or scare of cougers & bears etc,) we don't now. Of course the dealer will never be able to "recreate" the problem , so it cannot be fixed.

 

[robsibe]

Thanks I'll try to adjust the valves this weekend and I'll let you know if that helps.

 

[Adrenaline Vince]

Check exhaust leaks.Usualy back fire is a lean problem,check intake boots there a problem on the brutes. Also setting valves may help. As for jetting if I can remember right should be 148,152 I think. Check your plugs and look how its burning.

 

[lucm]

Help. My 05 Brute force 750 backfires when you let off the throttle at high RPM's. It is completly stock but has recently been rebuilt. Carbs are clean and I don't think there are any air leaks. Anybody have any suggestions on what it could be? Maybe the jets? What size should I go to? Thanks

Mine does the same thing so I have learned to never let off on the gas..:d

Seriously though, its either and exhaust leak or a jetting/carb issue.

 

[loose cannon]

valves need 2 b set!!!!!!!!!!! or exhaust leak