Just a thought but have you changed the plugs out? Running super rich might have fouled the plugs and you are probably still running super rich. I would change the plugs and put the programming back to settings with just the exhaust added and see what happens.

 

If it had a full exhaust on it, it would have been running lean, not rich. Possible to burn a valve when running too lean. I would have a compression test done on it to check the valve train and rings. Since it's built as a mud machine, any number of things could be possible. Mud and water ingestion is tough on engines. Good luck.

 

I would agree with you on an older carbed machine, but with newer machines that are EFI the computer will see the lean condition from the free flowing exhaust and normally overcompensate and create a rich condition. The low end of the rpm being lagging in his case is screaming rich condition. Pull a plug look at it and post the results of the plug, or a picture will speak a 1000 words for you.

 

Agree on checking the plugs to diagnose lean vs. rich conditions. Also might want to run some seafoam through it in case injectors are a little gummed up.



Rather be riding, instead I'm using Tapatalk

 

These machines don't have an O2 sensor on them, so they will not adjust the air/fuel mixture on their own. It's a pretty basic system on these machines, really nothing like what is on todays modern vehicles. That's why a programmer is needed. Hopefully it is just a case of fouled plugs, but it doesn't seem likely to me.

 

Thats odd lol. I figured it would have an o2 on it. I havent really investigated that deep yet as i've only had my machine for a few weeks now. I guess my train of thought was that for the big mountain riders they would want a o2 sensor so the machine would adjust itself for different altitudes but I stand corrected. Touche'

 

I am not too smart on the rich lean Programmer exhaust stuff, but mine is the same way on the got to give it gas to start it, I had tightened the throttle cable as that will stretch a tad over time, so you can try to tighten that a bit, or if there is a way to adjust the idle RPM maybe you just need to bump that up. Tightening my throttle cable helped alot, it is just a rubber boot in between the throttle and pod on the handlebars.. Good luck...

 

I just tightened mine up and it now will start without me pushing in the gas. Thank you.

It still seems to lag really bad... then when i get to about 5 mph or more it will take off. I havent figured that out yet

 

I'd check/adjust the TPS voltage.

 

I would start with plugs. If they are originals, they might be fouled which is very common with 850's.

If they turn out good, next step would be a compression test. If someone was riding the hell out of it (which they obviously did as a mud machine), and they had an untuned full exhaust on it, they have a very good chance of a burnt up valve. Which would cause power loss, backfiring, hard starting, etc.

 

The polaris dealership put new plugs in it. they were champions. that was about a week ago and i havent rode it much and they are already turning black. I went to the dealership today to try and get some NGK iridium plugs, they ended up giving me the wrong ones, so tomorrow im stopping back by and getting the right plugs. Ive read on other forums that some people have had starting problems or problems taking off and iridium plugs have helped, so im gonna try them out.

I have noticed that it back fires quite a bit when im slowing down.

 

Air fuel mixture for sure. You need to have your computer tuned. Lack of back pressure can cause tons of power loss. Get her tuned or put the stock exhaust back on. Doubtful you damaged anything, although not impossible.

 

It still seems like all my power is there... except for when i first take off.

 

Sounds like my machine. what RPM does your machine idle at?

 

Before you do anything else I would run Seafoam through it. This is a good idea no matter if it is running properly or not as it will clean the fuel delivery system out but clean out your top end if there is Caron build up etc. How is the air filter? Clogged air filters will cause air/fuel to be out of balance especially at lower speeds.

 

Could be a couple issues. The 850s run rich on the low end and opening up the exhaust and lowering back pressure can cause effects like that on low end being a bit lean off idle. The clutching in them is also very weak from 0-15 or 20mph. Makes them feel lazy and slow off the line.

 

Second law of EFI, Polaris:

Thou shalt never use the throttle cable adjustment to adjust idle speed

Throttle cable must be adjusted so when at idle, the electric contacts inside the throttle handle are making clean contact. That will result with the cable having just a small amount of slack.

Check other threads on Throttle Cable.

I would check:
1- proper throttle cable adjustment including clean contacts inside the throttle handle.

2- Vacuum leak.

 

Could this be a timing gear slip like what is happening on several 13's? I have read of at least one case of it happening on a 12 as well. This will make the plugs foul out. It may not be slipped all that much, but this song sure does sound familiar to some other threads.....

 

hence why im hear, i think thats the issue with mine. dealer is dicking me around, i brought my machine home. going to dive into it soon and try and find the issue.

 

When you solve it, I hope you will give us a report.

 

Good Day to all

I am new on this forum, What a gr8 forum to be on, I need some help as well, I have also bought a second hand 800 EFI sportman and it runs like n dream, but recently I come across a problem after we have played in the mud a bit, while i was driving my quad suddenly stopped and a smoke cloud appeared from underneath my quad. All were well afterwards but now I'm sitting with a problem when i exhilarate slowly it feels like it shutters and then go, When you are full speed its fine, the problem is only when you start to go forward slowly you can feel as if the gears or CV joints doesn't make good contact, and it graps graps then when you exhilarate its fine

I have taken it to a workshop and they have replaced the universal joints but still the problem is there, Its not the belt nor the clutch, what else can it be,

 

Sounds like you may have burned a spot on your belt.

 

I have had it at a polaris dealer in South Africa, but they say nothing is wrong with my belt, the problem only happens when you from n standing start and you leave the exhilaration slowly, after that its goes fine, could it be the drive ketting inside the gearbox

 

My guess is you timing jumped a tooth some how. My 13 850 did same thing. I bought tps, tmap, throttle. Throttle cable. Ect and nothing fixed it. Finally but the bullet and ordered new bearings and seals and rings and pulled it apart timing was 1 tooth off.

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Thanks, but my chains are very stretch, reason why i say that is the nut underneath were you drain the oil is heavily scratched at the end by the chain, I need to purchase 2 x chains,that is what the dealer says, the bearings were the chain runs on are 100%, reason why I need to purchase it directly from overseas is the cost involved, the dealership asked me to much for the chains to be imported, The cost involved to import through them is about R 8000.00 ( $800)

Have you got a contact there whereby I can order through

Thanks for your help

 

Charl, my reply was not intended for your issue. You need to start a new thread and not high jack someone else's. That way people may be able to answer your question directly. I am stating only what I found wrong with my quad so maybe the guy that started this thread may look to make sure his timing is correct.
Good day aye

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apologies if my mail sounded bad, I appreciate your thoughts and suggestions, I will take this up with the workshop if they must maybe look in that direction, But if I need part where can I purchase it from, South Africa are crazy with their prices