Carb Issue, Bogs out completely beyond 1/4 throttle

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B

bellringer

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Bellaire, MI
Hi guys, Newbie here. I have a 2001 Warrior that I just bought, Thought I had a minor carb cleaning issue but man was I wrong! I took the carb apart and it already looked clean and I could tell somebody had messed with it because of screw driver marks on various screws and on the jets.
The problem I'm having is it starts fine, Idles fine and I can even drive it down the road, As long as I don't go past 1/4 - 1/3 throttle!! But as soon as I hit that spot in the throttle position it falls flat and will even quit running all together if I hold it at that throttle position. I can burp the throttle and it will take it fine, As long as I don't go past that "spot".
The clutch/brake switch has been disconnected from the previous owner and it will rev well past 2000-3000rpm (guessing on that without tach). I have taken out all the jets and orfices that will come out and cleaned them out and sprayed cleaner down each of the ports they came from and got cleaner out another port (which should mean they're clean right?)
I stretched the excellerator pump spring a little (No change).
IF I spray carb cleaner thru the carb intake as I give it full throttle it WILL rev up. (So that tells me it's carburetion rather than rev limiter or ignition problem) Everything seems to point to a fuel passageway being plugged but I can't find one that seems to be.
Oh, And i checked the intake rubber/aluminum boot and can not find any cracks or splits. I even tried moving it around while running to see if rpm would increase/decrease and it did not. Nor did it change when I sprayed oil all over it. (Which made a mess I had to clean up!!)
Please tell me someone out there has had this problem and can point me to exactly which passageway might be plugged.

HELP!!! I've gone through this thing 4 times now and am out of ideas!:argh:

Oh, and I did go through the forums for the past day and a half looking for anything that sounded anything like my problem and checked everything that was mentioned.
Help, I'm dying here, I just want to :atv:

Gary
 
What do you have for mods? Cause if it's modded your prob running stock jets and your running lean.
warriorbar-1.gif


03 Yamaha Warrior
PRM front bumper
AC nerfs
3 1/2" rear spacers
Custom slip on
More to come
check out my vids on YouTube
-Atv Mayhem
 
There are no mods that I am aware of or can see. With the exception of 2) 1.5" holes cut into the air box top, But I duct taped them off with no change.
 
Are you getting good flow out of your tank? Float height set right? Sounds like maybe not getting enough fuel.
 
Yep, Got good flow from tank through valve, also opened the bowl drain and drained almost a quart through carb drain and it was running out the drain hose much faster than the engine could possibly use it. I'm going to take the carb off again and soak it for a couple days just in case there's mud or something clogging a passageway and will check the float level to be sure but I believe it's right in the 1/2" range that I hear people speak about. I did put a float level clear hose gauge on it and the level was aprx. 1/2" below the seam checking it ON the quad.
I wish I could find a schematic of that carb that showed the fluid passage way for the needle and main jet so I knew which ones to really concentrate on, I just KNOW that's what's got to be plugged somehow. One of them has to be plugged COMPLETELY because once I reach the point where those curcuits should be kicking in it just falls completely flat on it's face. Not so much as a sputter, Just that BOG sound.
I also have a yamaha Timberwolf I just bought and rebuilt the carb on it cuz it wouldn't even idle and after cleaning (and I through in a rebuild kit) it runs like a raped ape! The only reason i mention that is although I'm not a mechanic I'm pretty mechanicly inclided and do understand the principles of carburetion. But this darn thing has something wierd going on and it's got me stumped. But please DO keep throwing thoughts out there and maybe somebody will come up with something I just haven't checked yet. :tup:
 
Ok. Pull the bowl and the main jet and inside the venturi where the needle goes into the brass thing (emulsifier tube). Pop that tube out with a long screw driver or something. Just be careful not to bend the needle. The tube should come out the bottom where the main jet screws on. Clean that tube and make sure all those holes are clear and the place on the carb that it goes in. put all back together and see how she runs.
 
Yep! Did that. I pulled the slide out the top along with the needle, Then unscrewed the jet from the bottom and pulled the brass tube out of that plastic or composite tube, it comes up thru the top into the venturi. Then I sprayed carb cleaner as best I could through that plastic tube and even put my finger on the bottom, filled it with carb cleaner and then put a low pressure air hose on it and blew it through the hole that's in that plastic tube and out the passage way it feeds. all the holes in that brass tube (Main nozzle) are cleaned out (I think there were about 6 little tiny holes)
2 things I did notice that I'm not sure are right are:

1)When I lift the slide and needle up they seem to be very loose in the nozzle, Is that normal?
2) The needle is Not visible from the bottom through the jet, Is that normal?

If I blow into that jet and open the throttle the air flow does gradually increase through the jet. (?)

Do you think it's possible that they dunked the quad and got Muddy water in the carb and the carb cleaner jet spray just won't break up the mud?
I Truly believe it's got to be one of the passage ways in the casting of the carb is partially plugged because EVERYTHING you can see Inside and Outside of the carb is spotless!
 
Last edited:
OK, I used a hypodermic syringe and forces SeaFoam through every passage in the carb I could find, Then blew them out with air. I checked and raised the float level. There were 3 removable jets in it, the needle jet said 120 on it and the one just ahead of it was a 45, the 3rd one which if I remember right was in the bowl of the carb did not have any markings on it.
After cleaning everything (Again) I did the excelerator mod everyone talks about except I had some little plastic nipples that fit on there much tighter around the shaft and I got a nice 1/4" stroke out of it now.
Then I put it back together and installed it and it runs a LOT better, But I STILL don't have use of the whole throttle. It runs good up to about 3/4 throttle now and then starts bogging. So I am SURE it is a carburetion problem and it has to be there's something wierd in one of the passages because I even ran an appropiet size torch cleaning tip through each jet and forced Sea Foam through ALL the passages. I just can't figure out what the hell they could have gotten in that carb that I can't get cleaned out. I'm going to try finding someone that has an ultrasonic cleaner that I can submerge the carb in and let it work on it and put a stock rebuild kit in it and see what happens. I'll report back after i do that but that won't be for at least a week because I haven't ordered the kit yet.

Just in case that doesn't work, Is there and economical decent replacement carb that anyone might recommend?? I saw one on Ebay for $169 that "Looks" exactly like my Mikuni but they say it's not a mikuni but rather a "replacement" but they didn't mention what brand it is.
Here's a link to it, Anybody got any input or knowledge on it?
http://www.ebay.com/itm/Yamaha-Warr...320&pid=100011&prg=1005&rk=1&sd=190832067423&
 
I just got one of those put in the other day. It actually is imprinted on the top with Zoom Zooom Parts. It's like they manufacture themselves or something. It was an exact fit for mine and only took us less than an hour to install, including adding in a fuel filter in line. It runs like a champ!
 
What's your elevation? I believe stock main in 145...

warriorbar-1.gif


03 Yamaha Warrior
PRM front bumper
AC nerfs
3 1/2" rear spacers
Custom slip on
More to come
check out my vids on YouTube
-Atv Mayhem
 
WOW! Trick questions! I "believe" if I remember right we are 792' above sea level. So, IF your correct on that 145 I would be lean for my altitude, Correct? IF I order a rebuid kit I assume they come with the factory stock numered jets, right? And you have to order larger or smaller from someplace like Jets-R-Us if you need bigger or smaller.

I see here another member got one of those Mikuni knock offs and loves it, What's YOUR thought on them? Or any other carb I could put on without a lot af "Adapting" that doesn't cost $400-500.

Just a little background. I'm a 59yo guy that used to snort around back when I was in my 30s but got out of quads for a long time but have since retired and live up north in MI with trails all around us and we decided to get back into it to ride (sanely) around and of course on occasion I like the feel of kickin' it in the butt. So I'm not a racer, and I don't want this quad to be so radical that I got to be tuning and wrenching on it all the time. A nice "peppy" stock (dependable) quad is what I'm after.:atv:
 
You'll prolly need a 145 main (stock). In your other post, you said you don't see the size of the main jet. Now your saying it's lean if stock is 145. What size is your main jet?
 
Maybe I'm not communicating it correctly. The jet with the needle is a 120. The jet right next to it in the upper half of the housing is 45. I'm not sure which is called the main jet.
There is also another jet that can be unscewed from the bottom bowl half that has no numbers on it. Those are all the "removable jets I could find.
 
On the bottom of the tube is a hexagon shaped jet. That's the main jet. What number is it? 120? If so, then ya it's lean.
 
NONE of my jets are hexagon. But the one on the bottom of the needle jet tube IS #120. It's about 3/8" diameter on the head of it with a scewdriver slot in it and it has a brass washer under it.
Then there is another jet right behind (or ahead depending on how you look at it) that is down inside a tube that is cast into the aluminum body of the carb that is about 3/16" in diameter on the head (1/8" at the threads) that has the #45 on it.
The remaining jet I could remove was in the Bowl of the carb (bottom half) and it had NO numbers on it at all.
 
The 45 is pilot. It should be ok. The 120 is main. You need prolly 145. But you would have to check your plug after you install it. I'd just get a 145 cuz 120 is def too lean. Oh, sorry on the hex, been working on a Keihen and forgot what Mikuni had. My bad.
 
That's part of my problem, I KNOW SOMEBODY before me has been wrenching on this thing (They rounded out half the screws that go into the carb) So I'm not starting with a "Known". But if 145 is stock and I have a 120 then I think I'll go invest in a jet and try that before looking for another carb.
I WILL report back and Thanks for all the input!
 
Where in MI are you? I'm up north all the time maybe I can help you out
 
I live in Bellaire, MI. It's about 4 miles east of Torch Lake. Or 15 miles nw of Kalkaska. Your quite a bit south of me in Holland I believe.
 
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