2012 Polaris Pro 800 163 Hesitation/no power.

[karsonkeaton11]

Hello! I'm new to the forum thing, I have a 2012 pro 800 163 that I bought in Feb 2021, I took it to McCall Idaho a couple days after buying it and it ran amazing no problems at all. Then I come back home in Washington, I load it up one morning to go riding maybe 4 days after getting back with no issues whatso ever. I get up to the snow park fires right up first pull warms up, I unload it no issues. I shut it off to finish getting ready to head out, I fire it up I start to head up the trail and then all of the sudden it like " falls on its face" has no power, super bad hesitation. It would hesitate at low RPMs then I would hit around 4700-5500 RPMs it would all of sudden get a huge burst of power and take off and then it would start to slow itself down and hesitate again with no power until I got the RPMs up to 5000 range it would take off again. I am clueless on what could be wrong, I already replaced the fuel filter, and nothing was wrong with the exhaust reeds. I'm very open to any suggestions! Thank you.

 

[Betterview]

Bad spark plug, plug wire, spark plug boot. First things to check. When it is running bad check each side of the Y pipe to see which cylinder is cooler, that is the side to go checking.

 

[Minndave13]

My advice- check your electrical connections- actually pull them apart and check their condition. Check for loose wires, burnt connectors etc. But, I don’t think that’s your problem. I also would take out your exhaust valves and clean them, if they haven’t been out in a while they will be real dirty, but again, I do not think that is your problem. I think your problem is the tps (throttle position sensor). That damn sensor is known to cause many different problems!!! I had a 2010 800 that suddenly would not run once it got to operating temp. I had a parts sled so I traded all parts (fuel filter, reeds, wiring harness, everything) it wasent until I replaced the tps ( literally the last thing I could replace) that it ran right again. I then bought a 2014 Pro RMK with a “ sometimes would die, but start right back up” problem. Problem never really surfaced until I went on a trip. I died once but it was more of a problem that there was about a 1 to 2 second hesitation. I brought it home, cleaned the exhaust valves ( more as a needed service) but the hesitation was still there. So I purchased a new TPS, installed and adjusted. The hesitation and dieing went away immediately.