On my 03 trailblazer 400 I have been scratching my head for over a week now about a fuel overflow problem while it's running. I figured since most of the carb(except main jet) is about 8 or so years old it could be time for a rebuild because I was getting a slow drip out of the lower overflow tube all the time. And when I looked at the needle it had a slight indentation in the viton tip and the seat looked to have a weird black ring just outwards of the opening. So I cleaned it out and put in a moose rebuild kit and it stopped the leaking while it wasn't running. Then I started it up and everything seemed to be great until I ran down my road and came back and parked and smelled gas. I checked it and it wasn't leaking. Started it up and it instantly started shaking gas all over the place. I've rechecked the needle and seat, adjusted the floats from one extreme to the other till hell wont have it and can't figure it out. Also, the kit has a brass(i guess???) needle and only an aluminum washer where the seat screws into the carb. Shouldn't there be some sort of o-ring somewhere in the setup? I know with the viton tips they're not necessary, but I would think there should be something for metal on metal contact to help seal. Any ideas?

 

This needle valve has changed from the original 3130495 that was used for years with no problems to 3132385 and I never had a problem with the replacement!. The "packing' or washer behind it is just a fiber washer.If you have replaced the valve,have adjusted float level and it leaks while running,then you probably need to replace the float arm and float pin.This is a simple carb and when the carb is upside down the float arm should be parallel wit the carb body.The shop manual will also give you distance from float arm to the carb body on its side,just as the arm touches the needle,BUT just check it upside down!!Still sounds like a worn float and the float pin need to be replaced. I always used the Oem replacement needle valve and fiber washer and have used the Moose kit on several makes that we serviced other than Polaris with no problem. I've never had to replace a float itself from damage ,BUT you can pull the small plastic cap holding each float in place and check for any holes or leaking floats themselves. There is NO o-ring in this needle valve system!! Its either the float arm and pin worn also,vibrating if its too loose and worn on the pin,plus the pin could be grooved down OR the Moose needle valve packing(washer) should be fiber,not aluminum,but should still seal off the valve in the carb body. This engine vibrates quite a bit and wears out needle valves and float arms more than the others. OPT

 

I have pulled the floats off and checked them and they both look fine, but one of the rods that hold them in place has a wear mark on it towards the top end(upside down) of the rod. The other does not. But even with the mark both floats slide up and down just as smooth as I think they should. should I take my old fiber washer off the old seat and swap out the aluminum one? The float arm has clean marks from where the floats and needle have been touching them for years but they have no grooving or anything like that, they're smooth while lightly draging a razorblade point across each place. The Moose kit I have is part# 1003-0082, which I got just for the needle and seat because it was $18 for the whole kit instead of $50 for just the needle and seat from polaris. I'll try readjusting the floats again, but I'm VERY low on hope of that working but I'll try it again. Other than that could it just be a bad needle/seat? OR

 

Where the most wear on the float arm is not really where it touches the float tabs,but at the back where the pin goes through. The float arm opening begins to enlarge as it constantly rubs up and down on the float pin.They usually get "wobbly" and the float pin in a lot of cases will start to grind down also and become smaller in diameter which adds to the problem: hard to adjust the float to stop it from over filling and leaking! If you're having this much problems on overflow,I would just replace the pin,float arm,and you can buy the little fiber washer and probably keep the Moose needle valve as they are pretty close to the oem parts,at least the ones I've used. I only used OEM parts on Polaris,but Moose kits have worked okay for me on Honda ,Yamaha,and Kawasaki. The CHEAPEST place I've found on parts is Cycle Parts Warehose on oem parts. About 8 bucks for the float arm, 3 bucks for the pin,and 40 cents for the washer! OPT

 

I did get a chance to get out there today and take a look at the float arm and that's probably what it is. The arm has wiggle room in all directions on the pin. I'll be ordering the parts later this week and I'll post that it's fixed when the parts get here. I do have another question though, in setting the float arm do I set it to level with the little pin pressed on the needle or without? I've tried it both ways with the worn parts, but when I get the new ones which is better/correct?

 

Install the new float arm and pin While upside down,make sure the float arms are level with the carb body with the needle valve installed! If it does happen to drip a little after installed,then you can bend the small tab just a "LITTLE" down which will shut of fuel a little quicker. Most of the time I just had em level and no problems! This is where the "book" isn't always right on how to measure the float height! At least not on the old 350 and 400 carb. Sounds like if you have a lot of "wiggle " room on the old float arm like you said,this should be the fix. The new float arm will come with the small adjustable tab level,try it that way first and adjust only if needed to keep the float arm level with the carb body. Keep us updated OPT

 

as for the little spring loaded pin in the top of the needle valve does that need to be pressed into the needle when setting the float arm or without any pressure on it? It's not the peice of wire that holds the needle to the float arm, this just sticks out of end of the needle and makes contact with the arm first. I've never seen this pin on any other type of carb before when setting float hight.

 

NO pressure on the needle! Just let the float arm rest with the needle attached to it and make sure the arm is level with the carb body!! The little plunger in the needle is normal for this carb. On some of the older Yamaha and Suzukis, etc some needles don't have the plunger tip,but most still have the spring wire!! OPT

 

That's what I figured but wanted to make sure. Other than mine, i've only worked on 2 other offroad carbs, but neither of them has the little spring loaded pin like mine and most of my carb experience is on automotive carbs. But I'll be ordering the parts tomorrow and will update when the parts arrive. Thanks again OPT!!

 

ok, Parts installed, float hight set and still has the same problem. Adjusted the little tab down on the float arm to cut off fuel earlier, problem didn't change. It doesn't do it at idle, just when it's coming back down then it puts out DROPS of gas out of the lower overflow tube. Never had any problems with the upper, but I'm about ready to just pinch it off and see how it does. Any other ideas besides pinching it off or hanging it higher than the carb?