Brute Force 650 Starting / idle problems
 

I own a 2007 Kawasaki Brute Force 650. After the first 3 months of owning this unit it became very hard to start and would not maintain idle. It will crank and crank, & crank, then backfire through exhaust and carb before finally starting. The only way to keep the unit from dying after startup was to manually turn the idle up about 3 turns. After the engine warmed you would have no engine braking, and very high idle, you would again have to adjust the idle, down this time. Once it warmed up it ran great and restarted fine.

I took into two dealers 5 seperate times to correct this problem. The first three trips did no good what so ever. The fourth trip they finally corrected the problem, only to have it last for 2 months. They claimed they adjusted the valves, reset idle stop on choke plates, and synchronized the carbs. Now 2 months later I have the same problem. It does not seem to be a cold weather problem since it has occured off and on since July.

Kawasaki intially admitted to me (while unit was under warranty) this was a known problem with this engine and to have dealers contact them when I took it in, as they had a remedy for it. As stated before the first three times they (dealers) could not fix it. Now that the unit is 2 months out of warranty Kawasaki is claiming that I did not properly maintain the unit (simply a bunch of BS) and not willing to work with me. I am amazed at how well documented this problem was under the warranty period, only to have them argue with me and blow me off now.

If anyone has seen this problem and has a remedy I would appreciate any help. Since Kawasaki is no longer willing to accept responsiblitly for this problem I am sure it is going to cost me a small forturne to correct a problem that should of been corrected under warranty.

FYI[img]i/expressions/face-icon-small-disgusted.gif[/img]
This unit has also been in two other times (while under warranty) to have the valve cover gaskets redone because they leaked oil.

Brute Force 650 Starting / idle problems
 

I have a new 2007 BF 650I, sure hope this doesn't happen. it is a little hard to start but it does idle. thanks for the heads up.

Brute Force 650 Starting / idle problems
 

Usually the dealer cant fix it, because it would require the jetting , be made richer, and the emissions would be higher, and by law, they cant do, or suggest that. They have to follow the kawasaki recomendations, they cant just go on their own.
Either the pilot jets need to be bigger, or it might just need the mixture screw richened. The idle circuit is too lean (backfire and popping thru the carb are both symptoms of lean).
Do you try to use only pure gasoline? If you use ethenol blended gas, try a full tank of pure gas (no alcohol), and see if it improves. If it doesnt, then the jetting needs to be corrected. Just remember, the dealership cant and wont do it for you. Either you find someone who can, or you need to do it yourself, and its not that big of a deal.

Brute Force 650 Starting / idle problems
 

jhb,
"After the first 3 months of owning this unit it became very hard to start... "
So, quad started fine during the first 3 mo? If so, this is not a factory carb setting issue. Something else has changed during usage. However this still could be carb issue like poor quality fuel prematurely gumming up or some tiny debris "partially" clogging up the pilot circuit of your carb.

"very hard to start and would not maintain idle..."
This is a very typical symptom of partial clogging of the pilot circuit and/or tight valves.

"They (dealer) claimed they adjusted the valves, reset idle stop on choke plates..."
Ask this dealer to show you where the choke plates are on your BF650 carb. There ain't any. You got hosed.

"The fourth trip they finally corrected the problem, only to have it last for 2 months..."
Valves would tighten up after about 50~100 engine hrs on BF. Do you use that much in 2 months?

Do following:
1). Check/replace plugs.
2). Check compression
3). Check choke system. Actually it is a fuel enrichening system, there is no actual "choking" on the BF's twin carb system and choke is a mis-leading terminology on BF. It is a small plunger (there is one for each carb) that opens and closes to provide extra fuel when you push the choke lever. Check to see if the plunger compelety opens when you push the choke lever all the way. And check to make sure the plunger moves freely - no sticking.
4). Fuel gumming up is my bet. Get a $3 Techron fuel system cleaner (8 oz bottle) from WalMart and ride full one tank. This is a lot easier to clean gummed up carb than disassemblying the twin carb system. If this solves your problem, add fuel stabilizer into your gas tank next time when you are not riding the quad.

Brute Force 650 Starting / idle problems
 

Ok yes I probably do ride it that much. For the two months it ran good I apparently put 40 hours on it. That seems a little premature to me for a valve adjustment, but I am not a professinal mechanic. How do I check to see if the plungers are working? I can tell you that once engine starts on choke it runs ok for about 10-15 seconds, then you have to pull choke off because engine starts to sputter. This leads me to believe that the choke is operating properly, but again I am not a mechanic, and maybe the plungers are sticking. I have put new plugs in it, does not seem to help. Had a hell of a time starting it this weekend, spent 45minutes the night before the ride to load on trailer, and 1 hour the day of the ride trying to start. Changed the plugs out two times trying to get it to start. Both times the plugs came out damp with gas on them. I run 87 octane fuel in the BF that you would buy for a car, and do not put anything else in it.

Thanks for your suggestions hopefully I can pin it down

Brute Force 650 Starting / idle problems
 

The choke (I hate to use this term - fuel enrichening) plunger is located on the left side of the carb at the ends (one for each carb) as you are sitting on the quad. Just follow the choke cable toward the carbs. The single cable will split into two, one for each carb. Remove a small screw for a cap that holds the plunger which is a small piston shape (cylindrical) meta, maybe 1/4" dia, made of brass that is spring loaded in the aluminum bore of the carb. To check the proper operation of the choke plunger, with the cap open, push the choke lever all the way open position - does the plunger open all the way in the bore? Then, push the choke lever all the way to close position - does the punger close all the way in the bore?
Your problem sounds so much like clogged carb but how can it clog up if you put 45 hrs in two months? By the way the hour reading on your meter is not accurate - always more than actual because that's key on time not running time. Mix carb cleaner fluid in your fuel tank and see what happens - that's easy and cheap.
I don't want to underestimate you but just to make sure... you are not opening the throttle (like giving gas) when you start the engine with the choke on, are you? You shouldn't be.

Brute Force 650 Starting / idle problems
 

Yes,
That is the only way I can get it to start. I always try to start it choke off first, then go to choke on, and then push the throttle if need be. Here lately the only way I can get it to start is to open the choke, and mash throttle. I spent 1 hour trying to start this damn thing Sunday. We drained the ATV Battery, and another, changed plugs twice, (each time the plugs were damp with fuel) and then resorted to jump starting it from another ATV. We finally got it going, but it did take 1 hour, it was very cold out about 28-30 degrees. Once it started and got warmed up it ran really well all day, and always restarted fine. Once I trailered it home, (about a 30 minute drive) I could not get it to start, gave up and pushed it in the garage.

Brute Force 650 Starting / idle problems
 

I also start mine with the choke on and give it some throttle. I then turn the choke off and continue to give it gas so it dosen't die. I still give it gas untill it holds it's idle on it's own. then it runs fine all day.

Brute Force 650 Starting / idle problems
 

If your choke system is operating correctly and your carb is in a good health, when starting cold, opening throttle is not necessary. Actually, it would make the starting harder/longer (but eventually starts).
Here is how it should work:
When Cold:
Full choke, throttle closed, start engine. Slowly reduce the choke until it reaches normal idle rpm or just little higher, put in gear and start driving. Then completely turn off choke while moving. Even in average 20 deg weather here, I start my engine and get going in less than 5 seconds with this method.
When Hot/Warm:
Fully closed choke, slightly open throttle or as blipping, start the engine and drive.

Brute Force 650 Starting / idle problems
 

<div class="FTQUOTE"><begin quote>Originally posted by: jhb211221

Yes,

That is the only way I can get it to start. I always try to start it choke off first, then go to choke on, and then push the throttle if need be. Here lately the only way I can get it to start is to open the choke, and mash throttle. I spent 1 hour trying to start this damn thing Sunday. We drained the ATV Battery, and another, changed plugs twice, (each time the plugs were damp with fuel) and then resorted to jump starting it from another ATV. We finally got it going, but it did take 1 hour, it was very cold out about 28-30 degrees. Once it started and got warmed up it ran really well all day, and always restarted fine. Once I trailered it home, (about a 30 minute drive) I could not get it to start, gave up and pushed it in the garage.</end quote></div>

What you are describing is very normal on BF's!
They start great withouth the "choke" when it is hot outside, but when it is open all the way it will only run 10-15 second and will begin to "choke". You can get a feel of it and readjust the choke lever to be barely "on" and it should idle until warm up with no problems. It you can't "get a feel" of it, simply give it a little throttle for 30 sec. or so, and it should idle fine. You will have to let it worm up or it will run bad. I guess that is corrected on the 08 BF's with fuel indjection.

Brute Force 650 Starting / idle problems
 

So have you been able to solve your starting problem? I am haveing the same thing happen with my 2006 650i. It actually started better when it was colder out. Now that it is in the 40's it seems that the choke is too much and giveing it some gas is not enough. Last night after cranking on it for an hour and using every possible combination of choke and throttle I finally managed to get it to start. After the raw gas cleared out and it warmed up it ran great. I drove it around for a half hour then parked it in the garage. Now this morning I ran the battery down again and it won't start. It acts like it wants to start and will backfire ocassionally. I pulled the front plug and it is wet with gas. The last time I changed plugs I put in Autolite so I am going to go find some NGK's today and see if that helps. I just ordered the Dynatek CDI unit this morning also because it is supposed to give a hotter spark and fix the timing offset. I was wondering if maybe this offset is contributing to the hard starting on Brute Forces? If anyone has ran into this problem and can tell me what they did to fix it I would be all ears.


<div class="FTQUOTE"><begin quote>Originally posted by: jhb211221

Yes,

That is the only way I can get it to start. I always try to start it choke off first, then go to choke on, and then push the throttle if need be. Here lately the only way I can get it to start is to open the choke, and mash throttle. I spent 1 hour trying to start this damn thing Sunday. We drained the ATV Battery, and another, changed plugs twice, (each time the plugs were damp with fuel) and then resorted to jump starting it from another ATV. We finally got it going, but it did take 1 hour, it was very cold out about 28-30 degrees. Once it started and got warmed up it ran really well all day, and always restarted fine. Once I trailered it home, (about a 30 minute drive) I could not get it to start, gave up and pushed it in the garage.</end quote></div>

Brute Force 650 Starting / idle problems
 

OK I am still having cold start problems. I decided to remove the carbs and check what the previous owner had in the way of jets. I found a 150 in the front and a 155 in the rear. The mixture screws were only out 2 turns so I set them at 2.5 turns. I checked the needle valves and they don't seem to be stock. They are tapered and have a clip. I thought the stock ones had a straight shaft? The clip was in the 4th groove from the end and had 2 washers on top of that. I thought you were suposed to place the spacers under the clip to hold it up when it was fully seated? Anyway I am going to leave the carb off until I can get the stock needle valves and then start jetting from scratch. Does this sound like I am on the right track?

Brute Force 650 Starting / idle problems
 

[img]i/expressions/face-icon-small-happy.gif[/img]

OK I think I have this thing figured out finally. I bought the stock needle and jets and put them in the carbs and set the mixture screw out 2.5 turns. After I put everything back together it still wouldn't start by cranking with the starter. I then switched to the pull starter and it started on the third pull. [img]i/expressions/face-icon-small-confused.gif[/img]
A couple years back I had 1977 Kawasaki 650Z and it would not start unless you turned the lights off to save juice for the ignition. Evidentally the spark was weak.
I put a Dynatek CDI in the Brute Force and now it starts right up every time! It must be a combination of the hotter spark and over riding the 6 degree offset that Kawasaki builds into the stock CDI.
Perhaps if Kawasaki wouldn't muck up their timing on purpose they wouldn't have such a bad reputation for having hard to start Brute Forces! I almost bought a Grizzly instead of the BF 650i just because they tend to start when you want them to.
Now I have to go back and see if my jetting changes didn't cause a new problem! [img]i/expressions/face-icon-small-frown.gif[/img]

Brute Force 650 Starting / idle problems
 

OK I finally got things right! The Dynatek CDI didn't fix my starting problem after all but setting the valves did. Seems they were too tight to close all the way at low speed RPMs especially with the automatic compression release. The Brute starts right up now at the first press of the starter button. The Dynatek does make it a lot snappier on the throttle. It will bring the front end up anytime you blip the throttle. I'm just glad to have it running again. If anyone else begins to have starting problems and it has been 500 miles or more since you checked the valves than I would start there.

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Brute Force 650 Starting / idle problems"></title><script src=
 

[img]i/expressions/beer.gif[/img] sorry about that last one.
so, i have 2 bf 650s. 2005,2006. 05 starts great, 06 starts like crap and getting worse since cold weather.(20s-40s). did everything mentioned above before searching for help, surprised about all the others w/ problems. down to adjusting valves. how do i do this????? i'm afraid this is above me. any help would be great, with some guidance i think i can do it.

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Valves are easy to adjust. Have you downloaded the manual for the 750 Brute Force? The procedure is the same for a 650 as in the 750 manual. Intake valves are set to .15mm and the exhausts are set to .25mm.
1. remove the left side plastic, Battery and tray, and tin tray under the electronics.
2. remove the pull starter housing.
3. remove the plug covering the inspection hole for top-dead-center.
4 remove the rear valve cover being careful not to lose the rubber o-ring.
5 place a large socket over the nut where the pull starter was and rotate the crankshaft counterclockwise while watching the rear valves open and close until you see I-R (which is a sideways T and a R), both the intake and exhaust valves should be closed and the top of the sideways T should be lined up with the notch in the inspection hole to be at Top_Dead_Center. Be aware that the mark comes around twice per firing cycle but it is only at TDC when both valves are closed.
6. Loosen the locking nuts on the intake valves (which are the valves closest to the carbs) and use a screwdriver to turn the adjuster screw until they are a 1/4 turn out from contacting the valve. Hold the screw in place and tighten the locknut. Do that for the other intake valve next to it. You can check the clearance with a guage but for me a 1/4 turn out has always been just right.
7. Do the same for the rear exhaust valves except turn them out 1/2 turn from contact.
8. replace the rear valve cover making sure to keep the o-ring in the groove, a little grease helps.
9. remove the front valve cover and repeat the process watching the valves as you rotate the crankshaft counter clockwise. Look for the valves to all be closed at the same time as the top of the T (of sideways TF) lines up with the notch in the timing inspection hole.
10. set the front valves one at a time, 1/4 turn out for the intakes, and 1/2 turn out for the exhausts.
11. replace the front valve cover, timing hole cover, recoil starter, battery tray and battery, and side cover
12. start and enjoy the improved performance.

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thanks dude. allready adjusted the valves. starts better than when i first bought it. got the info through another thread. only been a member of this site for a month or less and saved a crapload of cash allready. gotta love america.

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Need suggestions. After about 2 years of using my 2006 650 BF 4x4, I started having problems starting it. I don't use too much. I have approximately 500 miles on it. Anyway, it was working in a weird manner, until it finally couldn't get it to start. The only way to make it stay on was have it choked at all times. The instant that I would move the lever to the opposite side, it would die. Again, it would start only if choke lever all the way to the left. I know that's not normal operation. When I crank to start it, it attempts to start, but it doesn't. I'm suspecting that it might be the gas filter or the carbs are simply dirty. The manual that came with it is not very helpful when it comes to troubleshooting. I will certainly appreciate any assistance from you all. I want to attempt to figure out the problem on my own before I decide to take it in. Thanks.

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curious, when you get it running, once it warms up does it run fine? does it start ok then?............. or can't you even get it started at all?

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so i've been having all the same problems everyone else has been. I took my quad to the shop three times, and they said they fixed it, but it still ran like crap; even worse after the second trip. So I had some buddies work on it, and they got it to sort of run, but it still is hard to start and won't idle, so I was curious how to check the timing and where I can get an instructional manual. Any ideas??

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I had the same problems with my 2006 650 brute force. It used to start with a little throttle just fine and run all day but i noticed that the valves were out of adjustment just by the noise they were making. I brought it to the dealer for an adjustment and thats when the trouble started. It wasn't that hard to start but it wouldn't stay going and every time it shut off it took longer to get it going again. On the third trip they finally cleaned and adjusted the carbs and readjusted the valves for the third time and it works like a top. however... i'm noticing that it is wanting to shut off before it is fully warm. but that could have something to do with the cold damp weather here in Newfoundland... it likes to get down around -30 celcius with the wind sometimes and i'm using it for plowing snow.

hard to start, cold natured bf 650
 

It' almost certainly one of the idle jets plugged - which is very common if you use ethanol gas. Remove the carburetor bowl and unscrew the idle jet (long skinny brass jet with tiny hole through middle and crossholes). Using a single wire from a wire brush rod out the hole. If it's bad, you may have to soak it or even replace it. Push through the crossholes, too. Adjust the valves while you're at it since you will have removed most of the stuff in the way. Replace the plugs. If the carb bowls have trash in them you'll need to thoroughly clean the whole fuel system. ATV engines are super sensitive to fuel quality - only clean, non-ethanol! These motors will start on the first turn and are not cold natured when everything is right.

I just discovered this revived old thread. Mine takes a while to warm up and then runs fine. I choke it to get it started and once it starts, I turn the choke off and give it light throttle a few seconds at time until it warms up. It purrs like a kitten once it warms up. From some of the posts I have read, I'll stick to the old saying of if it ain't broke, don't fix it. Yes, you can't start it up and drive off immediately like an efi model but I've experienced that with every carb atv I've ever owned. First start of the day just takes some patience. Give it about a minute and a half to warm up and you're good to go.

Weltys71
 

I have a 2007 650 BF that I bought in March. I rode it 3 time and it ran great. The last time
We stopped about halfway thru our ride and it didn't want to start for nothing but it finally
did. Ran great the rest of my ride that evening. I parked that night and the next I was gonna
ride it wouldn't start!! Actually it hasn't started since. I took the carb apart and cleaned,
changed the plugs had a couple buddies look at it. The last guy said it was blowing when
it should be sucking when he checked the compression! I'm at my witts end with it...please help!!

First thing with a non starting engine is check for sparks. If you have good sparks and new plugs and it still won't start, re-check the carbs, make sure you can see through the jets, and it is all too easy to re-assemble them wrong if unfamiliar with them. Next check compression, if low on one cylinder it could be valve adjustment, low on both, probably either wear, though this doesn't come on suddenly, or a partial seizure. Either way, adjust the valves and, if that doesn't bring compression up, strip the top end of the engine to find the fault. If compression is OK, check valve timing in case it has jumped a tooth or two. If it has you will need to find out why, stretched chain, or faulty tensioner.