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Discussion Starter · #1 ·
I have a 98 magnum 425 4x4 and when the handle bars are parallel with the front end the tires are turned a bit off to the side. Is this an tie rod alignment issue or is there a way to take the steering shaft and loosen it up and turn it to the correct position and then retighten it? I loosen the bolts at the top of the shaft and pulled up the key and choke holder to get he gas tank out so not sure if that's what caused it.

My second issue is the bottom of the carburetor has the bleed screw and its dripping from it. I pulled be old one because I seen it was leaking when the gas was on. It was severely rusted and the tip was missed shaped so I bought a new bleeder screw. I installed it and when the gas is on it still drips a bit. What would cause this? Does that assembly do two purposes where it's a bleeder to flush the system and then also have a tall tube inside the pan that acts like an overflow that's always open so if the carb lets too much gas in then it goes out that tube? Or is it that the opening for the screw is just shot and looked like the old bleeder screw tip? The quad is running fine. Starts on a dime. Any help would be appreciated.
Thanks,
Jason
 

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The screw is loosened to drain the carb. They come with a long plastic tube the runs to the bottom of the frame. Usually ends up missing at some point. The tall tube inside the carb is an overflow. It bypasses the screw and lets fuel drain out onto the ground instead of into the engine. Float valve is probably shot and leaking. Overfills the float bowl and through the overflow.
If your handlebars were straight with the wheels before you loosened it to take the tank off then I would suggest you take it apart and re-assemble it. Must have gotten something out of alignment there. If not, then the adjustment will be with the tie rods. Set the handlebars and loosen up the tie rods. Shorten or tighten them to get the wheels lined up again. Should have about 1/8" toe out.
 

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Discussion Starter · #3 ·
PHP:
The screw is loosened to drain the carb. They come with a long plastic tube the runs to the bottom of the frame. Usually ends up missing at some point. The tall tube inside the carb is an overflow. It bypasses the screw and lets fuel drain out onto the ground instead of into the engine. Float valve is probably shot and leaking. Overfills the float bowl and through the overflow.
If your handlebars were straight with the wheels before you loosened it to take the tank off then I would suggest you take it apart and re-assemble it. Must have gotten something out of alignment there. If not, then the adjustment will be with the tie rods. Set the handlebars and loosen up the tie rods. Shorten or tighten them to get the wheels lined up again. Should have about 1/8" toe out.
I took the carb apart tonight because I ran the four wheeler for two to three minutes and when I put the throttle down all the way the fourwheeler was acting like it was bogging down and the run normal for a bit then bog down and would keep doing that. When I let it sit and run idle in my barn for a couple minutes it would run normal and then change to a lower tone like it was bogging down. then after two to three minutes of running it would start dripping under the bowl. That tube is missing on this atv also. Im going to post a couple pics to see what you think caused this. Which parts do I need to redo the float and is there anything else i should redo on the carb while I have it apart.

Thanks for all you help,
Jason
 

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Discussion Starter · #5 ·
Handle bars

I don't remember if they were straight before I took them off or not but the only thing I took apart was the bolts that held the steering shaft to the key ignition, choke and gear light bar. So I don't think that probably caused them to be off. When the handle bars are parallel with the front of the quad the wheels are both facing the same way and they are a couple
inchs to the left of being straight forward. It's like they both need to be shifted to the right an equal distance to be straight with the handle bars.

Thanks for your help. I posted a couple pics of the carburetor to see what you think of it.
Thanks
Jason
 

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That carb needs a an ultrasonic bath! The green crud is water that reactivated with the brass jets and other components in there. Water you say??? Yes, usually from fuel containing ETHANOL that sits for a period of time in the carb and separates. Called phase separation. The bare minimum, it may need new jets, but gonna take some time soaking in a good carb cleaner. Ultrasonic cleaner with the proper solution would clean that right up I bet. For the alignment issue, best way to explain is to get service manual. Haynes manual number 2508, about $18-$25 on ebay. Involves some wrenches and a tape measure. Hard to explain over the net.
 

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Discussion Starter · #7 ·
That carb needs a an ultrasonic bath! The green crud is water that reactivated with the brass jets and other components in there. Water you say??? Yes, usually from fuel containing ETHANOL that sits for a period of time in the carb and separates. Called phase separation. The bare minimum, it may need new jets, but gonna take some time soaking in a good carb cleaner. Ultrasonic cleaner with the proper solution would clean that right up I bet. For the alignment issue, best way to explain is to get service manual. Haynes manual number 2508, about $18-$25 on ebay. Involves some wrenches and a tape measure. Hard to explain over the net.
Thanks for the info. Here's an update. I do have the manual and got the alignment figured out and discoverd the ball joints will need to be replaced soon. I took the carb apart with knowing nothing about them and just doing a lot of research. I bought a carb kit for i think a 2001 sportsman (whatever the atv shop told me) which had the same jets except the main jet. The float was blocked three quarters the way on the backside of the filter by like what almost looked like hair. I cleansed it with a spray can of carb cleaner. Replaced a couple
Of the Jets and the new float assembly. Now when it gets going the mid to high end it screams like it should but to get going it acts sluggish and hesitates and it's not the same every time. Sometimes it only happens for a sec and other times it will do it for three to
Four seconds. But once u get going it's no problem. Then when you slow down it usually backfires a bit and I think it's coming from where the manifold of the engine meets he exhaust tube at the joint. Looks like the motor is getting carbon on it and he joint has this wire mesh looking stuff sticking out of it. So I guess my next question would be what would cause the sluggishness at the take off and is that joint in the exhaust from not being packed tight causing it to backfire?

Thanks for your help already!
Jason
 

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I would still bet the carb has a dirty passage somewhere. Or the main needle slide diaphragm is tore, ripped or not pliable anymore. Take the vacuum cover off the top of carb, pull black slide out and look carefully at that diaphragm. For the exhaust, can you post a pic of what we looking at???
 

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Discussion Starter · #9 ·
I would still bet the carb has a dirty passage somewhere. Or the main needle slide diaphragm is tore, ripped or not pliable anymore. Take the vacuum cover off the top of carb, pull black slide out and look carefully at that diaphragm. For the exhaust, can you post a pic of what we looking at???
Tomorrow I'm taking the carb off and gonna do a full disassemble and soak it in a carb stripper and then reassemble. I will take a picture of the exhaust tomorrow morning and put a pic on here. Thanks for your help, I appreciate it and can use any input.

Jason
 

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Discussion Starter · #10 ·
Picture of the exhaust leak where I think it's backfiring.

I would still bet the carb has a dirty passage somewhere. Or the main needle slide diaphragm is tore, ripped or not pliable anymore. Take the vacuum cover off the top of carb, pull black slide out and look carefully at that diaphragm. For the exhaust, can you post a pic of what we looking at???
This is picture 1
 

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Discussion Starter · #11 ·
Picture of the exhaust leak where I think it's backfiring. Pic 2

I would still bet the carb has a dirty passage somewhere. Or the main needle slide diaphragm is tore, ripped or not pliable anymore. Take the vacuum cover off the top of carb, pull black slide out and look carefully at that diaphragm. For the exhaust, can you post a pic of what we looking at???
This is picture 2
 

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Yep, you have an exhaust leak there....Loosen the exhaust mounting from that point back, pull the springs and separate at that joint. There is a donut gasket in there that is probably shot. Clean up both parts as well as you can and put a new gasket in it. It is a carbon, fiberglass (not sure exactly) type material which explains the mesh. They are cheap I think and fairly simple to replace. Could be part of your backfire.
 
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