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2006 Polaris Sportsman 700 Twin EFI
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Discussion Starter · #1 · (Edited)
TLDR: sportsman EFI tried to defeat me after i spent 2000$ on rebuilding it, my experience chasing down every cause for rough idle, backfiring, bogging, sputtering and running lean.

Guess ill start by saying this; don’t give up when ur bike gets them gremlins! .. also always give every simple cause a really good look before u tackle the bigger possible ones.

so i’v had my bike for a good three years or so now but it always was pretty thrashed and i decided to give it a rebuild and cleanup. New tires and wheel bearings, exhaust gaskets, needed a new front cv, front wheel spacers, full fluid and filter service, .. may have also threw a holesaw and welder at the muffler and a few other knick knacks plus giving attention to common problems these bikes will have. Well... after bringing it back to life IT started, the common problem these bikes will have at some point- backfiring, popping through the intake, running lean, bogging under 3000 rpm then cleaning up to ride fine, erratic idle and stalling (then somehow i made it run rich before i found my problem).
So i started reading and re-reading these and other forums trying to figure out what my problem was and i did ALL OF THEM.
Cleaned, inspected and tested spark plugs, the boots wires and coil packs, cleaned the ground for the coil pack.... cleaned and looked at the intake boots, entire intake and box and it was fine i thought. Cleaned the throttle body and tested the TPS and T-bap wiring... nothing yet, so i adjusted the throttle cable and inspected the WOT safety system, bike still hates life. Okay what next... replace T-BAP and clean my battery to frame grounds. Nope still sounds like a herd of elderly leaving the Thursday card game; lots of pops and bangs and occasional odd noise, so i re-adjusted the whole exhaust (exhaust leaks wont cause these problems i believe unless maybe the manifold looks like a cheese grater and if your wondering my personal opinion/experience is modding the stock exhaust on these bikes wont result in a big enough change in fuel/air ratio to immediately cause catastrophic problems or hurt the bike, it may make it run lean but mine does not if yours does it could not be getting enough air to match or have small built up restrictions in fuel delivery system).Alright lets try what i didn’t want to do, inspect 85% of the harness, plugs, fuel lines, grounds, relays, injector harnesses and other hidden possibilities. Pulled the fuel pump, cleaned and blew it and the in-tank screen out(yes i had replaced the frame filter and no i didn’t put it in backwards). Now it runs rich and runs just as bad.. at this point i think it might be valves.. please god not the valves. i more or less have explored everything that i have read up on and thought of. Ready to go home on the 6th day of hitting this thing with wrenchs, back to home to read up more(there was nothing more to read up on or videos to watch i looked through it all at this point) but i thought i’d look at one more thing that i had previously inspected without pulling it off and apart - the rubber hose that goes from the top of the valve cover back to the intake box, pulled it out and took the silver heat shield off of it and found a two inch cut down the side of it...not where it had rubbed through the shield. Why does it always have to be the simple things that we overlook sigh grabbed and cut a new one and slapped it in, runs great and goes like a cheetah jacked up on redbull.
I Win.. and feel stupid

i’m a certified mechanic with experience in all fields and am currently employed as a ATV/UTV mechanic so this was not my first time and probably wont be my last time... but hey, way she goes

this post is about my experience and to create a new thread on these issues and to generalize the common list of causes for these issues within my own story, ill freely give my opinion or guess if you’re having the same issues as i did. All i can say is if running like crap at idle, bogging, backfiring and running lean, inspect all the rubber closely from the airbox to the instake on the motor. Heres a few pics after i threw my care package of goodies at it. Cheers

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wow, sounds like we are in the same school just different halls. I have a 2005 Sportsman 800 efi that I decided to rebuild. Powder coated the suspension, replaced all bearing and axles, stator, voltage regulator, injectors, plugs, fuel pump, fuel pressure regulator, TPS Sensor MAP Senor and plug, Temp sensor, new hoses, winch, front brake handle and a ton of other small items. Still have rough idle, fuel pressure was way high at 67PSI. Now it will at least idle, even as low as 850RPM but very rough. Idle back to 1050 and when you take off it bogs then takes off like a banshee. Checked the exhaust front to back, cleaned it up had the pipes ceramic coated and put a better heat shield on it.

I would love to replace the mufflers but the only thing I can find are either used or aftermarket, and the latter thinks you want them loud. This is a hunting machine I need stealth. I will post some pictures.
 

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2006 Polaris Sportsman 700 Twin EFI
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Discussion Starter · #4 ·
wow, sounds like we are in the same school just different halls. I have a 2005 Sportsman 800 efi that I decided to rebuild. Powder coated the suspension, replaced all bearing and axles, stator, voltage regulator, injectors, plugs, fuel pump, fuel pressure regulator, TPS Sensor MAP Senor and plug, Temp sensor, new hoses, winch, front brake handle and a ton of other small items. Still have rough idle, fuel pressure was way high at 67PSI. Now it will at least idle, even as low as 850RPM but very rough. Idle back to 1050 and when you take off it bogs then takes off like a banshee. Checked the exhaust front to back, cleaned it up had the pipes ceramic coated and put a better heat shield on it.

I would love to replace the mufflers but the only thing I can find are either used or aftermarket, and the latter thinks you want them loud. This is a hunting machine I need stealth. I will post some pictures.
Two things i can think of for you to check for your idle is the TPS, if you took it out of the throttle body or swapped for a new one you could have adjusted your idle accidentally, look it up, all you have to do is loosen the torx head holding it in and spin it slightly while it is running until you get your idle right, there is a more complex version of doing this but i did not need to do that myself, i just adjusted it by ear. The other would be to watch your plug wires in the dark see if its’ arking out anywhere, mine was right at the back of the elbow on the top of the head; i don’t think that will cause the jumping ldle it usually makes them missfire and is hard to notice but hey these problems will compound so its good to check. Check into the tps on your bike, i ripped mine apart like 6 times until i found that one out ha, i just finished everything on my bike last week, fast as hell now its almost scary ha, heres an updated picture, love to see yours!
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