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Discussion Starter #1
I'm new here. My son and I have some experience fixing and flipping atvs but mostly Honda. Bought this 96 Trailblazer knowing it had a bad crank seal and carb issues. Bike would run but poured fuel out of the pull start assembly. Replaced the crank seal on that side. Now it will run for a minute with no fuel coming out of the pull start assembly but it floods out and shuts off. When the carb is disconnected from the intake and motor side, if you turn the fuel petcock to on it pours gas out of both end of the carb. We've been through the carb, made sure the arms that the floats push on are level with the float bowl. Still have the same problem. Any guidance would be greatly appreciated.
 

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If the engine will start with the carb off the intake, the crankcase is full of gas - remove the drain plug (#20 in the schematic) to drain the crankcase, fix the carb and try again.
 

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Discussion Starter #3
I didn’t mean that it starts with the carb disconnected from the intake. I’m just saying that if the carb is disconnected and you turn the petcock to the on position, with the bike not running, fuel pours out of both the air box side and the motor side of the carb. I just noticed the common carb issues thread and I’m now wondering if it’s the float needle and seat. Never seen this issue with Honda. Or maybe it’s a typical 2 strike thing. More familiar with 4 stroke.
 

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Discussion Starter #5
That’s what I’m trying to figure out. Does this seem to be the float needle and seat need replacing?
 

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Can't say - need the carb in hand to inspect. It is the responsibility of the mechanic to determine. Is the needle valve in good condition? Is the needle seat in good condition? Do the floats float? Do the floats float the the proper amount of float above the fuel? Are the pins the floats ride on straight and not corroded? Do the float pins have the limiter caps on them? Is the fuel line on the inlet pipe or connected to the float bowl vent nipple?

If you want to send me the carb, then I can determine what the problem is and fix it.
 

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Discussion Starter #7
Can't say - need the carb in hand to inspect. It is the responsibility of the mechanic to determine. Is the needle valve in good condition? Is the needle seat in good condition? Do the floats float? Do the floats float the the proper amount of float above the fuel? Are the pins the floats ride on straight and not corroded? Do the float pins have the limiter caps on them? Is the fuel line on the inlet pipe or connected to the float bowl vent nipple?

If you want to send me the carb, then I can determine what the problem is and fix it.
The floats float, as far as I can tell to the proper level. The pins are straight and not corroded. The limiter caps are in place. The fuel line is connected to the proper inlet. What I don’t know how to determine is if the float needle and seat are in good shape or not.
 

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Take the needle out of the seat and examine the tip of the needle - if it's all metal, look for a wear ring around the tapered tip - if you can see a wear ring, the needle and seat should be replaced - if rubber tipped, look for very fine cracks in the rubber, examine the rubber to see if it is distorted, swollen or otherwise damaged from exposure to alcohol - if the needle is good, examine the seat for a smooth edge on the hole the needle seats into - if there is any corrosion or imperfections in the edge of the hole the needle and seat should be replaced - if the needle is fine and the hole has a slight imperfection the hole can be reconditioned by finding a steel ball to drop into the seat that is larger than the needle hole and just smaller than the diameter of the seat bore - place a punch on the ball and tap the punch with a small hammer to reface the edge of the seat hole - DO NOT USE A DRILL BIT TO TRY TO RECONDITION OF THE SEAT - IT WILL RUIN IT AND YOU WILL HAVE TO REPLACE IT!
 

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Another thought - is the pin that contacts the needle arm on the float at the top or bottom of the float?

Maybe a pic of the float bowl with floats.
 

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Discussion Starter #10
Take the needle out of the seat and examine the tip of the needle - if it's all metal, look for a wear ring around the tapered tip - if you can see a wear ring, the needle and seat should be replaced - if rubber tipped, look for very fine cracks in the rubber, examine the rubber to see if it is distorted, swollen or otherwise damaged from exposure to alcohol - if the needle is good, examine the seat for a smooth edge on the hole the needle seats into - if there is any corrosion or imperfections in the edge of the hole the needle and seat should be replaced - if the needle is fine and the hole has a slight imperfection the hole can be reconditioned by finding a steel ball to drop into the seat that is larger than the needle hole and just smaller than the diameter of the seat bore - place a punch on the ball and tap the punch with a small hammer to reface the edge of the seat hole - DO NOT USE A DRILL BIT TO TRY TO RECONDITION OF THE SEAT - IT WILL RUIN IT AND YOU WILL HAVE TO REPLACE IT!
Thanks. I’ll inspect the needle and seat tomorrow. I’m pretty convinced that’s what it must be. Everything else seems to be correct.
 

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Discussion Starter #11
So, I couldn’t find any blatant evidence that the needle or seat was bad but replaced them anyway. No change whatsoever. Any other ideas what could be causing this?
 

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Got a pic of the insides of the carb? I would have to have the carb in hand to be able to SEE what's wrong. A keen sense of observation is a key factor in repair services.
 

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Got busy with work and kids. So I did some research and discovered that the float arms were out of adjustment. What I saw, on YouTube, said the needed to be between 22-24mm measured from the little rib where the gasket sits with the middle tab resting on the float needle. Tried everything from 22-24, still got fuel coming out of the throat when not running and throttle closed. Kept adjusting to 27mm and fuel finally stopped. When I open throttle fuel comes out as it should. However, when I close the throttle it continues to come out. So I tried adjusting the main needle to the deepest setting and nothing changes. I can try to post pics of you want. I’m not the best with technology.
 

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I'm still curious if the floats are installed right side up or up side down?

And I would like to see the condition of the tip of the float needle and the edge of the hole in the needle seat.

That's what I said - it takes a hands on examination.

140455
 

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I’ll try to post a pic when I get home but the float needle and seat are brand new and I’m almost positive the floats are installed correctly. The each day up and they are installed so that if the carb is mounted the words up would be right side up if that makes sense.
 

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Perfect - I can see by the pics that the carb is in some serious need of a good cleaning and the way the float arm is set, either it is failing to contact the pins on the floats during assembly, the fuel line is being put on the wrong nipple, the overflow pipe in the bowl is damaged in some way (split?), the floats are not floating or the new needle and seat are not shutting off the fuel for some reason.
 

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I know the float arm is set wrong. I started out with it set right and worked my way upon 1mm increments till I got where you see it now. Where it is now, it shuts the fuel off completely. Doesn’t even let any in the bowl. If I go back 1mm it won’t stop flowing when the floats come up. The floats are floating, at least they see if I have the bowl off and fill it by hand. I agree it could be cleaner. The fuel line is in the correct nipple . Don’t even think it would fit in any other nipple on the carb. It appears to be a bigger diameter. I’ll check the overflow line but I’m pretty sure it’s intact.
 
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