rmk 900 bogs and back fires

[aaron786@hotmail.com]

06 rmk 900 bogs and backfires, idles at 3000 rpm someimtes a little more once warm. sled will die or sputter and barely run when shifted into reverse, if you let it idles and slowly accelerate you usually get a 2-4 second burst of power up to about 8000 rpm then its just like someone hit the kill switch. if u put the sled from idle to WOT it will die almost instantly, pulled the tps sensor wire and it checks good with an ohmeter, have throttle bodies with new tps on the way, sensor was set at polaris dealer and it made it worse, now it doesn't start unless i unpplug the sensor to start or pull it about 10 -15 times. anyone got any ideas that i should check while i wait for my new tps and throttle bodies to get here ?

mods i have are- CPI single pipe, CPI glass pack twin muffler.
any help would be awesome :face-icon-small-hap

 

[guidoxpress]

leak on the ingtake boots...check for ANY cracks

get a new TPS harness...part number 2203165, about $35 (it replaces the weak wires on the OEM wiring)

whats the compression at?

whats the fuel pressure at idle?

check those out and report back...

 

[BIGGDAWG]

sounds like a fuel pressure issue or stator issue. check the stickies it tells you how to test them.

 

[aaron786@hotmail.com]

compression is 110 each cylinder, will have to get a fuel pressure guage from work tomorrow to check that and i will report back. do i order that harness right from polaris ?

 

[aaron786@hotmail.com]

sorry forgot to mention... polaris checked the reeds, intake boots and i dont know what else and called me to pick it up because they apparently cant do anything once it has a pipe on it at the dealer ?

 

[FatBoyzfrenchy]

TPS harness is the first thing I would look at. It's a cheap fix, just replace it on spec!

FBF.

 

[sleddude]

TPS harness is the first thing I would look at. It's a cheap fix, just replace it on spec!

FBF.

Yep sounds like a bad harness to me also.

 

[JessJMiller]

read can't get above 6000 rpm.

This may help also look at this topic as I had similar issues.

 

[05900]

Must be the pipe gettin in the way.....lol
How's the harness?......fixed?

 

[aaron786@hotmail.com]

k guys. got an update.

replaced the tps harness, and tps and set it, idles and starts better. still idles a bit high but nothing like before. starts normally too ( 4 pulls and fires right up), but still has one horrible bog anywhere above just over idle. backfire is gone too now. i talked to a independant sled mechanic and he said to do stator, he has the stator and flywheel as well as a computer that i can try. anyone think its a good place to try ?

 

[aaron786@hotmail.com]

will go to about 4400 rpm normally but after that if u dont baby it it dies, but if u barely touch the throttle u can get it to almost open right up ?

 

[aaron786@hotmail.com]

anyone got any other ideas ?

fuel pressure- 115 pounds
new tps, tps harness and set up by the video in how to's and double checked,
now starts and runs someone better, but nothing if u give it any amount of throttle, got a stator and ecu for saturday to try, any other ideas that i could pick up to try.? really wanna get this thing going.

 

[guidoxpress]

how is the throttle safety switches...are they loose, or have excessive play in the throttle flipper? just an idea...

did you read though the stickies (useful tips thread) for similar issues?

any check engines flashing?

 

[BIGGDAWG]

may be ignition coil, there have been 2 of them here lately that had similar issue and it was a coil, one was an injector.

 

[deanross]

If it is bogging down when you are at WOT have you checked your exhaust valves? They may be sticking and need cleaned. Just a thought.

 

[aaron786@hotmail.com]

have bypassed the throttle safety switches and it still does it, havn't done ignition coil only thing i've done is change the throttle bodies and tps and wires, and the other normal stuff, fuel pressure

 

[aaron786@hotmail.com]

changed the stator now and its a bit better but still pretty bad, checked fuel pressure with a crappy gauge and now only get like 45 psi, going to recheck tomorrow, anyone got any other idea's ?

 

[Z-Man]

check that fuel pressure again. If it is only 45 on an 06 you have a problem there.

 

[aaron786@hotmail.com]

redid a fuel pressure test with a good guage got 28 psi. am i right that a 2006 should run 116 psi ? should i be doing fuel pump or press regulator? dunno which to go after. any way of testing ? thanks for any help. really cant beleive the dealer didn't find that it had no fuel pressure

 

[mountainhorse]

Yes... The 2006 900/700's were the only ones to run double the normal pressure than all other CFi sleds... 8-bar (116psi) for the 2006 vs. 4-bar (58psi) for all other CFi sleds.

I am taking for granted that you have recently changed the fuel filter. (this is in line BEFORE the pressure-gauge tap location)

AND

You tested the fuel pressure with the sled not running using the fuel pump prime wires laid out in another post (keyword search for "prime" in the title in the Polaris section) and got the low pressure confirmed (this eliminates the possibility that it is a voltage/current problem within the sleds electric supply to the pump)

You need to pull the tank anyway.... So pull the tank, Remove the pump/flange assembly (PFA) and inspect the hoses and pickups in the tank. Different fuel and additives or just plain bad luck have been know to disintegrate the hoses... if the hose from the PFA head to the regulator is cracked... you will not have good fuel pressure... if the pickups are bad or the hoses going into the pump are bad... you will have poor fuel pressure unless the tank is full of fuel.

To see if it is the fuel pump AFTER you have checked the lines inside the tank to be OK...put the PFA back in the tank ... re-install the tank and hook up the plumbing again... then... with the pump hooked up to 12v just like you are priming the system... Check the pressure in the system, with a confirmed good gauge,... squeeze the RETURN line to the tank with smooth jaw needle nose pliers Or fuel line "pinch" clamp-pliers and see if the pressure increases and can maintain that higher pressure... if it does then you will have a good indication that the regulator is bad... if it cant make pressure... you will have an indication that the fuel pump is bad OR there is a restriction in the line before the pressure gauge tap.

Let us know what you find.