Polaris Sportsman 500 H.O. Idle & Sputtering Problems

[Ryann Racho]

So Id say about 2 years back I bought a 2013 Polaris Sportsman 500 H.O. off of my uncle. It ran perfectly, nothing wrong at all. I usually go mudding with it or just ride trails with buddies. So as you would assume, the quad is quite dirty from sitting for a few weeks.

 

STUTTERING PROBLEM: I noticed one day out of nowhere that in high gear at 15-20 MPH, I was already maxed out at 4500-5000 RPM  It would get to 15-20 mph, max out on rpms and start sputtering. It sounded like it was basically acting like it couldn’t go any faster than this.

 

IDLING PROBLEM: I was fu***** with the carberator the other day maybe thinking that is causing my sputtering, and now my idle will shoot up to 2600 on start usually, then I will turn the throttle adjustment down to the normal 1400. The rpms with then fluctuate 10-30 rpms back and forth repeatedly, it will then run for about another 30-60 seconds and the RPMs will slowly drop to about 900-1000 RPM and stall out. I replaced the carburetor and everything seems to be working perfect on that, no leaks and what not but it’s still acting strange. Also, I’ve noticed that when looking into the Electronic Throttle Control that two plates that aren’t supposed to touch have to be WAY past touching to even try to fire up. Even when set at a wide open throttle like that, I still have to give it some throttle to get it to fire up.

 

Here is what I have done so far: 

Checked the belt and clutch

Changed out spark plug (Last one was covered in carbon)

Cleaned the intake and air box

Replaced the carburetor

Replaced the inline fuel filter

Checked that all lines on carburetor are connected into the right spots

Checked If intake boot was cracked (Not from what I can see)

Unhooked and reattached new carburetor (About 4-5 times)

Cleaned battery terminals and battery off

Shut on and off Gas Line Cutoff Valve

 

 

 

My next thoughts are that maybe the TPS is fu**** up or maybe the Spark Arrestor is plugged with mud. I was thinking tomorrow to purge the exhaust and also check the ohms output on the TPS.

 

ANY HELP IS GREATLY APPRECIATED. I HAVE BEEN BATTLING THIS FOR WEEK AND REALLY WANT TO GO RIDING. THANK YOU!

[Frank Angerano]

The carburetor you installed was it an oem carb? 

I think your on the right track with the TPS. You can calibrate it with an ohms meter but probably better off buying the calibration tool.   

That throttle control and the plates your talking about also raise some concern so I would focus on what the spec says and review that it’s all working properly.  I had an older Polaris and the rev limiter inside the throttle on the  handlebars was flooded with water.   You could not notice it from looking  at it but when I opened it up the water was I see and everything was rusted.   

[BuggyMasters]

For the first item: if you are running that high an RPM at 20 mph, you most certainly have a clutch problem.

look at the video below. Your Polaris works very similar. The front part is a variator the 2nd part is the secondary. One of them is not working correctly.

 

for the 2nd: you are either fuel injected or you are carbureted. If you have a carburetor, you don’t have a TPS. If you are fuel injected, you have a TPS attached to a throttle body. What is your current setup?

for the throttle switch, take the throttle cover off and look at the setup and what happens with the contacts as you add slack to the cable. Then adjust the cable to just past where the contacts separate. 

 

https://m.youtube.com/watch?v=pptnRGTH_XA

 

Edited August 18, 2019 by BuggyMasters

[skidooer_3]

After reading your post you said you tinkered with cleaning the carb and now the idling is erratic. Double check the long needle to make sure the clip didnt fall off. Set it into 3rd notch and see what happens.

[Larry Fox]

Can I assume that you got it running?