Axys 800 RPM fade
- Thread starter jhurkot
- Start date
if any of you guys have a true fade issue? you will notice a change in engine tone. Polaris is using the cable controlled ex. valves for motor protection.
in some ways this is better then pulling timing, adding fuel, etc. what happens is the ecu drops the ex. valves to mid position. this doesn't allow the motor to spin much over 7400 rpm.
bad pipe seal at the wye pipe not allowing the pipe temp sensor to read right. the ecu adds fuel and pulls timing to correct this. the result lower then noramal rpm/power. clutch heat/belt slip. remember the ecu monitors rpm, vs. jackshaft speed, vs. load, etc. if something doesn't add up it closes the valves to mid position. air trapped in the cooling system. causing minor det. the ecu will take means to correct this. and for some reason it doesn't record that its happing in all cases. the means pull timing add fuel. the result loss rpm/ power. now the big one tps sensor adjustment. it has to be .700 at base. throttle plates fully closed. no higher. idle voltage .415-.417 max and the wot voltage no higher then 4.38 volts. any higher the sled runs pig rich. cooling off the pipe temp sensor. the ecu trys to correct this but its but the preprograming in the ecu is wrong. it pulls timing and adds fuel. pipe gets colder. not hotter. then it closes the valves. this is on the 15 sleds. won't know until I get a 16 in my hands weather or not something is changed? one other problem. the tps sensor is now on the ex. side. this changes the tps voltage when the sensor gets hot. I believe it disport's the plastic housing when this happens. this is why this fade issue with most is after 30-80 miles or so. and worse on warmer days. make a heat shield and put a piece of alum. foil tape right on the sensor.
and don't just take to a dealer and have the tps checked out on the d-wrench. it can be in Polaris parameters and still not be right. this is why the dealers can't find the problem. you must insist the check/adjust it starting at the base voltage with the throttle plates closed. not just look at a computer screen and say everything is fine.
Last edited by northstarrick; 08-03-2015 at 07:17 AM. That is the write up from Northstarrick which covers this issue but what i would like to know is how many people with there new Axys have over 500 or 600 hundred miles now and are still going strong or is there only one sled out there with this many miles on it
in some ways this is better then pulling timing, adding fuel, etc. what happens is the ecu drops the ex. valves to mid position. this doesn't allow the motor to spin much over 7400 rpm.
bad pipe seal at the wye pipe not allowing the pipe temp sensor to read right. the ecu adds fuel and pulls timing to correct this. the result lower then noramal rpm/power. clutch heat/belt slip. remember the ecu monitors rpm, vs. jackshaft speed, vs. load, etc. if something doesn't add up it closes the valves to mid position. air trapped in the cooling system. causing minor det. the ecu will take means to correct this. and for some reason it doesn't record that its happing in all cases. the means pull timing add fuel. the result loss rpm/ power. now the big one tps sensor adjustment. it has to be .700 at base. throttle plates fully closed. no higher. idle voltage .415-.417 max and the wot voltage no higher then 4.38 volts. any higher the sled runs pig rich. cooling off the pipe temp sensor. the ecu trys to correct this but its but the preprograming in the ecu is wrong. it pulls timing and adds fuel. pipe gets colder. not hotter. then it closes the valves. this is on the 15 sleds. won't know until I get a 16 in my hands weather or not something is changed? one other problem. the tps sensor is now on the ex. side. this changes the tps voltage when the sensor gets hot. I believe it disport's the plastic housing when this happens. this is why this fade issue with most is after 30-80 miles or so. and worse on warmer days. make a heat shield and put a piece of alum. foil tape right on the sensor.
and don't just take to a dealer and have the tps checked out on the d-wrench. it can be in Polaris parameters and still not be right. this is why the dealers can't find the problem. you must insist the check/adjust it starting at the base voltage with the throttle plates closed. not just look at a computer screen and say everything is fine.
Last edited by northstarrick; 08-03-2015 at 07:17 AM. That is the write up from Northstarrick which covers this issue but what i would like to know is how many people with there new Axys have over 500 or 600 hundred miles now and are still going strong or is there only one sled out there with this many miles on it
Last edited:
That is the write up from Northstarrick which covers this issue but what i would like to know is how many people with there new Axys have over 500 or 600 hundred miles now and are still going strong or is there only one sled out there with this many miles on it.........
J
jhurkot
Well-known member
Turned out to be a roller in my primary was sticking when force was applied to it. Put a spare clutch on today and it ran fine. Glad that was all that it was. When you're testing them make sure you push on them pretty hard when you spin them that's the mistake I made.
Thought so... I had exactly the same issue with worn rollers on my doo xp rather often. Glad it was an easy fix for ya.
Be very careful TPS if a very critical part of your engine tuning formula and most likely would have been consistently bad the entire life and not "fade".
My personal vote - this is not very likely!
We have heard of the belt issues and that is believable since belt deflection and belt stickiness is a very important part of performance.
We have also seen issues with the tuning above 45 intake air temp in the factory tuning. If your concern is when snow is piled up on the hood this is a likely culprit.
My personal vote - this is not very likely!
We have heard of the belt issues and that is believable since belt deflection and belt stickiness is a very important part of performance.
We have also seen issues with the tuning above 45 intake air temp in the factory tuning. If your concern is when snow is piled up on the hood this is a likely culprit.
For those that don't know, Joey is the dyno/tuning king at Bikeman. Thanks for taking time to reply with your tuning experience. There is probably always more than one cause for a broad range symptom.
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