Polaris Magnum 425 idles fine, runs terrible

[oliverstevenrjr]

I have a 425 Magnum that idles great but seems to flood out when I rev it up, sputters, backfires a little somtimes. No water in gas, good fuel filter, carb seems to be fine, good working diaphram. Plug change makes no difference whatsoever.

[outlander560]

it might be the float in your carburetor

[Ajmboy]

Is your choke working properly?

* Updated your thread title with manufacturer name.

[Honda420guy]

im not trying to be mean or nothin but its cause its a polaris... i swear

[face-first]

Friend

i dont know how this website works, probably never find out

i just printed this on another message

hope i can help

o.k. So it sputters and backfires, but, how the plug looks like when you change it?

This sparkplug description means a lot when working on engines and dont see it front and personal.

First, quick repair

check yar throttle cable for slack, too much is bad

eaven if it is ok, i whould recommend to open the throttle case, there is an electrical gizmo, little switch it is.

Dont remember very good, but i think the switch should remain close if you give gas, or not give gas

fire your bike

give it gas and see the switch action

you can close it by hand and may get a different output

now you may find out if and how set an adjustment for this cable

if not..

Well

more info.,.

And probably carb time..

Let me know

ps did you check for mice condominiums on the air filter box?

Did you store or did not use your bike for some time? For this one is easy

[DirtDemon]

Check the air filter, timing, valve lash, timing chain/tensioner and the inside of the carb. If it has not been run for a while, then the old gas in the carb could have gummed up. Check to see if it runs better with the choke on or off.

[Kyle2010]

Did you ever figure out your problem with the Magnum. Just curious, I'm having the same problems.

[yamaha]

No offense, but it probably runs poorly becasue polaris produces crap for the most part. Thier new 09 sportmans are much better, older ones are nothing but problems, get it running well and then sell the thing and get a quailty machine! yamaha, honda, suzuki, kawi or can am.

[outlander560]

PLEASE NO BRAND BASHING. if you dont have anything nice to say about Polaris or any other brand for that matter dont say it.

on another note Welcome to QuadCrazy

[DirtDemon]

Yamaha, I will re-enforce what Outlander said, there is no need to tell anyone that their ATV is crap. I have known several people who have owned Polaris ATV's and been completely satisfied with them.

Kyle, if you are having the same problems, I would take the same advise that the last guy was given, have you checked your air cleaner?

[Ajmboy]

oliverstevenrjr, how are you making out with this? What year is that 425?

[cobhc]

I have a 98 magnum 425 and have had similar problems. Next time it starts doing this, hold the yellow override button and see if this fixes it. works every time on mine

[rcrawford1110]

I have a 425 Magnum that idles great but seems to flood out when I rev it up, sputters, backfires a little somtimes. No water in gas, good fuel filter, carb seems to be fine, good working diaphram. Plug change makes no difference whatsoever.

A gummed up carb does sound the most plausable it may sound like its getting too much gas when in fact its getting to little. Also the machine needs good air flow to run properly change the air filter. Do a compression check to check valve seat also. More tech tips at atvwheelin.com in the tech tips.

[tatermade]

Take the air cleaner off, rev it up and see if gas is seeping into the air box. If so, your float is stuck or your needle isn't seating properly. Polaris doesn't offer a " carb rebuild kit " for my 95 425 Magnum ... you have to buy the individual parts and peices.

[Chris Ryder]

I just couldn't pass up this 98 Polaris with the automatic transmission , snow plow , brand new tires and brand new wench for $300 , he ran it a week before I got it , then it wouldn't start , I changed the stater and it idles with choke on , will not with it off , gotta really work the throttle back n forth fast to keep it running , it's got no smoke in the exhaust , so I'm thinking carb problems ? So far there's a lot of good tips here , great stuff guys thanks any good starting point , other than that yellow switch deal , I gonna try that next , already cleaned the filter n stuff , H E L P  !!!! 😂🤣😎

Edited August 30, 2018 by Chris Ryder

[Richard BOWERMASTER]

Somebody used the wrong oil, must use Polaris oil. Cam is wiped out. I had the same problem.