Quantcast
Jump to content

  • Do you own an ATV? Join our Forum!

    As a member, you can post in our forums, upload your photos and videos, use and contribute to our downloads, create your own member page, add your ATV events, and even start your own ATV club to host your own club forum and gallery.  Registration is fast and you can even login with social network accounts to sync your profiles and content.

Steve Howard

1997 Polaris Magnum 425 4X4 back fireing through the carburetor

Recommended Posts

Ran find shut down the quad next day would start and idle when you try to accelerate it would start popping through the carb got a rebuild kit soaked it in chem clean after break down for 12 hours on slow vibrate reassembled and adjusted per manual still the same thing any help would be really appreciated thanks and happy ridding  

Share this post


Link to post
Share on other sites


Only other thing I can think of is the throttle controller.  Are there two wires coming from that throttle ?  You would have to take the two screws off of the top of the throttle on the handle bars and see.  

I think that bike is to early to have the rev limiter on it but let me know.   

Share this post


Link to post
Share on other sites


On the throttle in the handlebars ? If so open it up and see what’s going on with the wires. I believe it’s a normally open circuit. It may be bad.  There is a plastic partition that separates the two contacts.   Sometimes that falls apart or water is inside the throttle compartment.  Separate the wires or disconnect them and see how it runs.  

Share this post


Link to post
Share on other sites

I took the cover off everything is clean and dry? I disconnected the wires from the throttle lever and still the same starts right up but wont accelerate  

Share this post


Link to post
Share on other sites

Ok good so that eliminates that.  I think your next move is back to the fuel.  I know you soaked/vibrated the carburetor good but sometimes the clogs are not as easy as soaking and if something got wedged in like a small piece of dirt or rust.    You may want to take that carb off and take a pice of wire and clean all the jets and ports out good.  I like to take a piece of brake cable from a bike and separate the strands and use one of the strands. It fits right in the little holes. Blow it out with air and re assemble.   

Make sure the float is good and set right and not closing to early.

Double check the gas petcock on the tank and make sure it’s clear and free flowing.  

This will eliminate any fuel delivery problems or questions. Put a fresh plug in and see what happens. 

If this clears it up great  if not you have to start looking at spark issues  or a breakdown in the ignition system. 

Double check that your kill switch is not faulty and shorting or a loose contact or full of water.  

Share this post


Link to post
Share on other sites


You can double check the wiring all the way back to see if there is a bust in the wires. 

Have you tested the spark for any breakdown.   I purchased an in line spark tester after another member pointed  me in the direction of the rev limiter and found my spark was breaking down due to the rev limiter having a fault but my problem was in the handlebars at the throttle.  I separated the wires and it ran fine.

Share this post


Link to post
Share on other sites

I bought a inline spark tester and checked the quad not loosing spark I can hod my hand lightly over the carburetor and I can get it up to about a 1/4 throttle and it starts popping through the carb real bad Thanks 

Share this post


Link to post
Share on other sites

Have you checked the boot connecting the carburetor to the engine for any cracks or leaks ? If you have good spark then I’m leaning toward a fuel problem.   It’s sounds like you did the right job on the carburetor but covering the intake starving the engine for air allows it to rev then it appears it’s within the carburetor. Is that bike gravity fed from the gas tank or a fuel pump ? 

 

The only other item I can take a guess at is the gap between the flywheel and pick up coil.  Take a look and see if that gap is within speck.  Double check the pick up coil is tight and all is ok inside that cover.   

Share this post


Link to post
Share on other sites

Get a can of carb cleaner. As you give it gas, give it a little shot of carb cleaner through the intake hole and see this extra fuel makes it rev. If it does, then you know you have a fuel starvation problem.

Share this post


Link to post
Share on other sites


Welcome back

I don't think it would be the cam, maybe its time to start going over the testable electrical parts. Regulator, stator coil and pick up coil.  
If you have the manual its stated what the readings should be as well as the process. We can also help you along, its not hard to do and all you need is a multi meter.  

Share this post


Link to post
Share on other sites

Absolutely could be a cam problem. Polaris had big problems with cams wearing out in short order back then. They fixed the problem I think in 2001. But do the test I mentioned above first and report back the results.

Share this post


Link to post
Share on other sites

I would agree with @BuggyMasters if it was a problem that slowly got worse. BUT for the atv to be running fine one day and the next day have this problem?  Polaris did have a cam issue but it showed up over time, not over night.  Spark plugs started to foul and the backfiring once in a while.   I just don't see it happening over night.  

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Similar Topics

    • By K L Buck Naff
      Trying to replace the carburetor on my 2003 Bear Tracker 250. Two brand new carbs in a row from different suppliers.   Both leak fuel out over flow and intake as soon as I turn the gas on. Any ideas. Am I doing something wrong?
    • By Daryl Mann
      Hey new to the page 
      having an issue with my carb slider jamming ect just replaced the carb with a good pre owned unit and seem to be having a similar issue 
      is there a home fix for this as a posed to buying yet another carb as the quads my daily transport and stuck without it 
      thanks for looking any help great full can also forward video of the problem I’m having if needed 


    • By Adrian Ciotinga
      So I’ve had this quad for the better part of a month, and it’s been hard to start since the day I bought it. Once it warms up it idles just fine and has plenty of power and starts no problem, but cold it takes 20 seconds minimum of straight cranking to start it.
      It’s not really too big of an issue, I’m just curious as to why it takes so long. Earlier today, it took me about 2 minutes of on/off cranking to get it to fire.
      i have attached a video of a cold start to show you what I mean.
      FullSizeRender.mov
    • By Dwight Williams
      Ok, so I bought this scream of a deal the other day - a 94 King Quad 300 for $40.00.  It's been sitting outside with no carburetor on it for about a year.  Its rusty, missing some parts, wiring is all cut up and spliced etc.  No seat, no racks but the plastic is all there minus the headlight housing.  Anyway, who can pass up a $40.00 quad right?  I get it home and looked at the sight glass for oil level, it's about 1/2 oil and 1/2 water.  I drain it, refill it and turn the motor by hand (recoil starter is missing) and it turns over just fine.  I worked on the wiring for about an hour and got it to turn over with the electric starter and got enough of it sorted out to get a spark.  Did a quick compression test, 70 lbs.  Wet test bumped it up to 90.  Ok, so rings and cylinder washed out with water for a year, not too surprised.  I thought 'what the hell' and sprayed some starting fluid in it and it ran for about 2 seconds - enough to show  it's got life.  Since then the compression has gotten worse, I can't get enough pressure to activate the carb diaphragm, therefore no fuel pump either.  The compression is now around 60.
        Anyway, my question is....is it worth it to try to get this thing going?  I tore the top end down today and the cam and one of the rockers is pretty worn.  I figured a top end job would be about $100 or so, depending on the condition of the cylinder but I'll probably have to put a cam and rockers in it as well.  Doing some research on ebay I figure I'll have to spend about $500-$700 to make the whole machine right again.  Much less just to make it run and use as-is but I won't really like it until it's right.  I don't mind doing the work, I actually enjoy it but I'm concerned about what all that water did to the rest of the internals, I can't really test it all out until I can make it run.
      I know it's a basket case but I'm not into it much at all, even if I do the top end and find something else wrong I'm still not out much.  I'm leaning toward ordering the top end parts and going from there unless you can convince me otherwise - any way to check the rest of the internals without tearing it down?  I plan on flushing the oil cooler before I do another oil change, I've drained it twice now and it gets milky almost immediately just turning the starter - I suspect the oil cooler is polluted badly.
       
      I'll get some pictures today if anyone want to see them.
       
      thanks!
    • By Ellery Zandt
      I have no idea where the antifreeze line coming off the thermostat goes too. The carb two nipples in the pic create a vacumme. Can someone help me on this please....!!! my email direct is [email protected]!!!!
  • Recently Browsing   0 members

    No registered users viewing this page.


×
×
  • Create New...