2013 brute force back firring

[crisscross1]

I took on some muddy water in the carbs. So I took them apart cleaned them with carb cleaner blew everything out. Now I have taken them apart 3x and still it back fires threw the carbs, but if the choke is on it will rev up. So I did the belt reset just in case it might help. nooo. Any other ideas other then selling it and buying a can am. When it cools down I will change the plugs.

 

[neilsleder]

I hate to be the one that tells you this, but my brute did this after I took on water. Would idle decent but not rev up and would pop though the carb. It ended up being the timing chain jumped one tooth. I think it was the rear cylinder.


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[crisscross1]

so how did you fix it? do you have to take the engine out?

 

[Cdnfireman]

Backfiring through the intake is either caused by timing too advanced or a lean mixture condition. If it runs better with choke on you might have a fuel supply problem. Check float levels etc

 

[TROLLCAT]

carbs are not in the intake boots correctly

will cause backfiring

 

[AreWeThereYet]

carbs are not in the intake boots correctly

will cause backfiring

As well as cracked boots,.. also vacuum lines missing rubber caps do this as well.

 

[neilsleder]

so how did you fix it? do you have to take the engine out?

If it jumps to much then it's a big issue, the valves will hit the piston. If only one tooth it good you just have to retime it. But there might be a bigger issue to why it jumped. You can check and repair it in the quad easy. Take the valve covers off and there are lines on the cam shaft that will line up with the head it's self. It's easy to see and check.
Mine was a 650i brute force and I bought a used 750 motor and put my 650 heads on it then used the hmf pipe that came with the 750. Turned that quad into a beast!


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[kingkris06]

As well as cracked boots,.. also vacuum lines missing rubber caps do this as well.

x2. also you need to have air box on quad .

 

[Ronaha]

Yup maybe if water gets into the jug,and the piston slams into the water it would cause timing chain to jump.

 

[Six point]

Had a similar problem with my old '05 Brute. Finally traced it down to a cracked exhaust header pipe way in the back. Tough to find. Fired it up cold and ran my hand over the pipe before it heated up ,was able to feel the exhaust blowing out. Heard it was a common problem caused by thin metal,heated up and then contact with cold water.

 

[crisscross1]

well the timing is just fine, but it still pops and doesn't want to rev up, unless you baby the throttle and coax it. It does run better with the air box on. Now it is time to reinstall the front cover and what a headache this is. Any other ideas? maybe I need to drill out the plug that goes to the adjuster screw and f.... with that