kawasaki brute force 650 carb problems

AverageJoe · 02-28-2010, 06:44 PM

Hey everyone. I'm brand new, so bear with me. I have an 06 650 Brute. I used to ride in WV quite a bit but had some kids and let it sit up. I am now trying to get back riding again. When I went to start it, the carbs were so gummed up that the throttle wouldn't move. Long story, short... I tore down the carbs, cleaned them, rebuilt them, dumped the fuel tank, adjusted the valve clearances, changed the plugs and put everything back together.

Here's the result:

1. It has gotten very hard to start when cold. It has always been cold-natured, but now after the engine cranks it still needs help from the starter for a couple of seconds. Also, I have to give it gas while running full choke for the first couple of minutes.

2. It sputters at low RPM. From idle to about 10-12mph.

3. At cruising (above 10-12mph) and high speed, it purrs like a kitten.

4. After it warms up... No choke to start. It fires right up.

I keep thinking, it's a pilot jet problem. That's the one jet I couldn't take out. My repair manual references pilot screws and jets, but the pilot jets on mine are press-fit in and don't look like those in the manual. There are no wrench flats or screwdriver slots to remove the jet. Anyone else have these type of carbs?

Will shimming the needles, like I've seen in other posts, solve my problems?

Any advice would be appreciated.

Thanks for reading.

brutemike · 02-28-2010, 08:06 PM

Quote: Originally Posted by AverageJoe

Hey everyone. I'm brand new, so bear with me. I have an 06 650 Brute. I used to ride in WV quite a bit but had some kids and let it sit up. I am now trying to get back riding again. When I went to start it, the carbs were so gummed up that the throttle wouldn't move. Long story, short... I tore down the carbs, cleaned them, rebuilt them, dumped the fuel tank, adjusted the valve clearances, changed the plugs and put everything back together.

Here's the result:

1. It has gotten very hard to start when cold. It has always been cold-natured, but now after the engine cranks it still needs help from the starter for a couple of seconds. Also, I have to give it gas while running full choke for the first couple of minutes.

2. It sputters at low RPM. From idle to about 10-12mph.

3. At cruising (above 10-12mph) and high speed, it purrs like a kitten.

4. After it warms up... No choke to start. It fires right up.

I keep thinking, it's a pilot jet problem. That's the one jet I couldn't take out. My repair manual references pilot screws and jets, but the pilot jets on mine are press-fit in and don't look like those in the manual. There are no wrench flats or screwdriver slots to remove the jet. Anyone else have these type of carbs?

Will shimming the needles, like I've seen in other posts, solve my problems?

Any advice would be appreciated.

Thanks for reading.

i jetted my 650i and in the process the i had to drill the cover off the pilot adjustment screw its simple that is what is going on with mine to it does the same thing when its cold out and we have had alot of snow here i just leave it like that warm weather is around the corner and it wont hert it a bit and ive been plowing alot of snow. hope i could help.

AverageJoe · 03-01-2010, 09:41 AM

Thanks for the post, BruteMike. You drilled the top of the press-in brass fitting to get to the the pilot jet to back it out? Do remember what size bit? Is this common knowledge? How did it get assembled that way?

brutemike · 03-01-2010, 10:42 AM

Quote: Originally Posted by AverageJoe

Thanks for the post, BruteMike. You drilled the top of the press-in brass fitting to get to the the pilot jet to back it out? Do remember what size bit? Is this common knowledge? How did it get assembled that way?

i cant remember what size just use a bit half the size of the insert and just drill thru the insert DONT PUSH HARD YOU WILL HIT THE SCREW you only have to go thru the insert and pop it out with a screwdriver or what ever works for you. i learned from doing every thing my self and talking to people on whats what. i preaty hard on my machine so ive fixed alot of stuff.i had a polaris before it just broke way to much and parts were alot more then kawie ones.hope i could help if u have any other ? just ask

blue brute · 03-03-2010, 03:45 PM

i think i used a 5/32 and just go slow and the plug should pop rite out, it stuck to the drill bit when i did it

AverageJoe · 03-04-2010, 09:10 AM

Thanks, blue brute. I don't have time to work on it during the week. I am going to tear the carbs down again this weekend. Hopefully, pulling and cleaning the pilots will resolve my issues. I'll let you guys know how it works out.

AverageJoe · 03-14-2010, 06:05 AM

Well, I finally got the problem licked. Last weekend I installed new pilot screws... same problems. Yesterday, I synced the carbs and I was still having lean problems. So, one last time I broke down the carbs. I pulled all the jets, floats, needles, etc. I broke out my original carb parts and compared them to the new ones. I found that the holes in the pilot jets were different. The original had visibly larger holes. So I cleaned and installed the original carb parts and put the bike back together. I fired it up and took it out. No more low rpm lean condition. Runs like a champ. Moral of the story: BEWARE MOOSE JET KITS! Now I can get ready for my WV trip next weekend. Thanks for the posts blue brute and brutemike.