# 05 Brute Force Running Bad, Help Please!



## Cwhitt05brute

Hello Everyone, my 05 750 Brute is sick. Here's the story, I purchased the bike from a friend who rides with our group every once in awhile, the bike was rode maybe once every month. So I bought it at a good price I thought, to were I could get it running right and make it my main bike. I took it up to a place called Performance Atv in Batesville, Ms to get the carbs cleaned and such. I'm not to good with carbs, especially dual carbs. Anyways they get them clean and I go to pick the bike up thinking it's gonna run right. Nope! I got it home and it hestiates when you hammer on the throttle, and during a hard accelration it pops and backfires constantly, and it backfires on deaccleration also. The choke cable is new, carb boots and intake boots are fine, airbox and filter are clean, the gas tank is suppose to be clean, running sea foam through it as we speak just to make sure. I took the spark plugs out yesterday and they are both black, I plan to run to autozone this week and get some new plugs and pick up a belt at got gear tomorrow hopefully. Anyone know whats wrong with my bike? It just isn't running like a brute should, nor does it have the power a brute should, it won't even pop the front end up because it hesitates so bad. Help Please! The Bike has 380 hours and 3800 miles, all stock, no snorkles, filter, exhaust, or jetting.


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## drtj

has the bike ever been snorkeled? sounds like a jetting problem. If the bike was snorkeled may needed to be jetted to run right then put the factory snorkel back on & never did rejet, or the shop may have swapped jets around by accident. Put your new plugs in & do a plug chop on them.(I think thats what its called) That will tell ya a lot. The rear cylinder usually runs a little more lean than the front so it should have a bigger jet.


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## hp488

The black plugs mean it is rich maybe they have the wrong jets or put the wrong jets back in, need more info on bike is it snorkeled, aftermarket exhaust,ect,ect. Let us know so we can give you a better answer.


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## drtj

the last line of the OP says all stock no filter exhaust snorkel or jetting.

Also they syncronization(sp) may be off if the shop messed with it any.


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## MeanGreenMan

Cwhitt05brute said:


> > I took it up to a place called Performance Atv in Batesville, Ms to get the carbs cleaned and such. I'm not to good with carbs, especially dual carbs.
> 
> > I got it home and it hestiates
> 
> > The choke cable is new,
> 
> > I took the spark plugs out yesterday and they are both black,
> 
> > I plan to run to autozone this week and get some new plugs and pick up a belt at got gear tomorrow hopefully.


> Cleaning single carb, dual carbs, triple carbs... basic is all the same. It's just takes more time. The difficulty or easiness is the same.

> You didn't check to make sure it starts/runs fine at the dealership? Start the engine, warm up and just rev it up at least in the parking lot if there is no place to test ride.

> Choke cable routing is little tricky on BF. It starts as a single cable at the top and it splits into 2. There cable can be twisted and hang open allowing more fuel than it should, causing rich condition. Also, choke on BF is not really a choke, but fuel enrichener - plunger in a bore. Since "choke cable" is new, the plunger should be clean, but the bore (the carb side) might have corrosion and the plunger can be sticking and partially open allowing extra fuel to carb. There are two of each, 2 plunger & 2 bores since dual carbs. Did dealer clean out the plunger bores on the carbs?

> Autozone does not sell BF belt. Is your belt deflection out of spec or anything wrong with it?


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## hp488

drtj said:


> the last line of the OP says all stock no filter exhaust snorkel or jetting.
> 
> Also they syncronization(sp) may be off if the shop messed with it any.


My bad I stopped reading it at anybody know what is wrong. Have to agree with meangreenman about the choke cable and routing of them, have had them hang on something pulling the plunger open and flooding it took some backtracking to figure it out.


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## drtj

yeah that slipped my mind too.


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## Cwhitt05brute

Thanks for the responses guys. When I picked it up at the shop I sat and let it idle for a bit and I revved on it some, It kinda hesitated on rev up but I figured it was just cold because it was cold when I picked it up. When I got it home and had room to ride it, it started it symptoms all over again. I got the new plugs and purchased a belt from my local kawi dealer. I will be friday before I can work on it because I'm in college and won't be home till the weekend. I got a new belt because my belt light started flashing last time I rode and put it in limp mode, not sure if my belt broke or if it's just old. But that's the least of my worries. I just want to get my bike running right and get it back to how a brute is suppose to run. I will check the choke cable when I start working on it, and I plan to put the plugs in and run it for the weekend and pull them back out and look at them. I wish a new set of plugs would fix my problem! Keep the idea's coming!


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## MeanGreenMan

Cwhitt05brute said:


> > I got a new belt because my belt light started flashing last time I rode and put it in limp mode, not sure if my belt broke or if it's just old.
> > I will check the choke cable when I start working on it, and I plan to put the plugs in and run it for the weekend and pull them back out and look at them.


If the belt appears to be in good shape like no frailing or separation, you can just remove a shim or two from the driven converter and make the belt tight again. Not necessary to buy a new belt everytime the belt light flashes. Also, after installing a new belt, you should really check the belt deflection and adjust the belt tension per manual and set it to the tightest possible within spec. In that way, you have the LONGEST possible service out of it before readjusting or replacing the belt.

> The way to check the plunger is to close the choke all the way (OFF). Remove the plunger out of the carb. Then try to pull out on the plunger to see if it would come out more or not. If it won't come out, that means it is fully closed and the cable routing is correct.

Here are two choke plungers that are corroded. If yours look anything like this, you know that your stealership didn't replace it AND they never cleaned the carb bore where the plungers sit in.









Here is after cleaning or how new choke plungers should look.









You may ask why is there corrosion forming?
Plunger is made of brass and the carb bore is made of aluminum. Two different metals in contact causes electron transfer, aka electrolysis, to stabilize the difference in number of electrons in their molecular structure.


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## Cwhitt05brute

Thanks for the pictures MeanGreenMan, I will check the belt and tighten it, if thats what it needs, the light came on and put it in limp mode about 2 miles from my house, It would run 10mph before it would cut out (limp mode) so I limped on home and I had to ghead back to school, so I couldn't check it out. The shop said they put a new cable on it and charged me 60 bucks for a new one, pretty sure that is a rip off, but I plan to check them. How do I take the choke cables loose? Take air box off, take carbs off? I'm new to brutes, never took a carb off of one. I don't have a service manual or owners manual for it either


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## drtj

become a subscribing member & you can download a manual for free!


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## MeanGreenMan

Cwhitt05brute said:


> The shop said they put a new cable on it and charged me 60 bucks for a new one, pretty sure that is a rip off, but I plan to check them. How do I take the choke cables loose? Take air box off, take carbs off? I'm new to brutes, never took a carb off of one. I don't have a service manual or owners manual for it either


First, get the service manual which will be the BEST investment you would ever make on your quad.

The shop charged you only $60 for part AND labor? 
I remember the cable alone is like $60.

Yes, you have to remove the air box. The manual says to remove the carbs in order to check the plungers. But I don't... If this is your first time doing it, you may have to. As more you do it, eventually you will get quicker. Look for 3 things when working on the choke cable:
1. Corrosion at plungers/bores.
2. Routing
3. Freeplay (if too tight, that will pull the plunger letting in extra fuel).
You may want to wait until you get the manual.


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## HeadC1

Clean the spark arrestor screen in your exhaust or just take it out. Sounds like it has abunch of carbon build up on it.


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## HeadC1

Also check your carb vent lines, make sure there's not a dirt dobber in there.


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## Cwhitt05brute

Alright everyone, I put new plugs in it Friday and it still ran bad. I was gonna adjust the valves Saturday but a buddy called and wanted to ride so I decided to go ride instead of fixing my bike. Anyways I get to his house and he rides my bike to see what he thinks the problem is, after he rides it, he walks down to his shop and gets his dynatek cdi box off his old brute that he demolished and plugs it into my Brute. He rode it down the road again and punches it and it stood straight up





















and it runs fine. It still pops out of the exhuast on accleration but I think it because th exhaust pipe is bad, when you get on the bike you can hear stuff rattling inside the muffler. Anyways I'm putting my buddy's stock pipe on it this weekend and maybe everything will be good to go!! Can't believe a cdi box fixed the problems, also he sold it to me for 60 bucks, is that a fair price?


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## bmabe114

is that the black cdi box? I am having samw problem as you were having...need to know if this fixed problem?


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## Cwhitt05brute

The Black Cdi Box is the one that they come with, I'm guessing something was wrong with it because when he plugged the dynatek in it made the sun come out of hibernation for my Brute, the dynatek is an after market cdi box that costs around 200 bucks I believe, my buddy sold it to me for 60. Anyways all in all it fixed most of the problems, it still pops out of the exhuast on acceleration but I think it has to do with the muffler being bad, and my choke cables need to be readjusted, I have to pull it over just a tad bit while riding to get it to run right.


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## Cwhitt05brute

Got the other stock exhaust pipe installed and it runs great now! No popping or backfiring anymore. The old stock pipe was rusted out inside and stuff was rattling around in there. Anyways, I plan to adjust my valves this weekend, or aleast attempt to, I have a manual downloaded so hopefully it will help. It doesn't wanna crank on a cold morning, from what everyone said that means the valves need adjusting. Also I need to check my choke cable again, it seems to stick a little.


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## THACKER

Mine is doing same thing carbs havte been completly cleaned in a sonic tank rejetted get it back from shop still pops and cuts out 300 down the drain take it back they adjust valves and put new choke cable on, helped alot but still hesitates around half to full throttle im lost on wat to do


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## Cwhitt05brute

THACKER said:


> Mine is doing same thing carbs havte been completly cleaned in a sonic tank rejetted get it back from shop still pops and cuts out 300 down the drain take it back they adjust valves and put new choke cable on, helped alot but still hesitates around half to full throttle im lost on wat to do


Man I understand the $300 down the drain, I spent $300 for a carb cleaning, new choke cable, and battery. Got it home and still ran like crap, it wouldn't even pick the front end up. I called a buddy of mine that is in our riding group and he use to have a 05 brute before he dunked it too many times and decided to get a new one, anyways he plugged his dynatek cdi into my brute and it ran like a new bike, I have to keep the choke open just a little bit for it to run right, I guess my choke cable isn't routed correctly and I put another stock muffler on it and that cut out the popping and backfiring. When you got your vavles adjusted did it help the bike crank up easier? I need to get that done this weekend, It still feels like my bike is lacking its full power potential, something isn't quite right


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## jeff700VTWIN

my 650 was doing the same thing, but i have snorks, it would run much better with the choke on just a hair, so i shimmed the carb needles 28 thou each and it runs perfectly now.


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## THACKER

Yes between the valves and choke cable, it starts upfirst click and idles crisp alot better then before.


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## ruglandj

I have an 05' brute. It had similar problems, id seemed to idle poorly, and was hard to start. I had the carbs done, and the choke cable replaced. This did nothing to it. Then my dealer's mechanic mentioned valves... So i checked them... They were way out (there was zero clearance) After i adjusted them she starts and idles way better. 

On a side note It is funny that you mentioned the Dynatek cdi... Mine burnt up on a ride last fall. I happened to have the stock one with me, once i installed it, it seemd to clear up the poping and cracking. I think it was not properly sealed as it seemed to act up after going thru deep & wet areas


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## bf420

i have an 06 Kawasaki Brute Force 750i. i recently put in a dynatek fs cdi box with a hmf slip on and a dyno jet kit. i re jetted for more fuel and moved the shims pn the needles and un screwed the air fuel screws. The brute ran good for awhile but recently it runs rough at all throttle levels except idle. i swapped out back to the stock cdi box and it runs considerably better. i was wondering if you thought it may be a faulty box or just jetting?


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## brute for mud

if you have to choke it a little it's a lean condition the choke is making it richer and if you swapped the box and runs better i would guess the box is bad


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