so fuel pressure is perfect. spark plugs are new and black as hell after very short time not even driving just start a few time.

 

What is up with the throttle? That is not oe. Is the slack adjusted properly? Fi likes to see the tps at idle position when starting.

Checked compression? Air filter? Did he use an oem injector? Put fresh fuel in?

 

no the trottle is installed since years never become an problem.
this atv runs great for years and the problem starts just now. nodody did enything.
compression is 150 psi.
injector is oem yes
airfilter is new last year checkt also

 

Unplug mas air flow sensor and see what it does.

 

Is that fuel pressure at idle ?
Does it drop under load (acceleration) ?

 

Good point. I didn't figure if it was fouling a plug that fast it was lean.

 

I testet an new MAP Sensor OEM BOSCH no change.
I changed the 2nd Injector also, no change.
tomorrow i will test an new set of spark plugs again and new spark plug cables.

 

Check fuel pressure while driving the machine.

 

fuel pressure is rock solid while driving.
so the atv spinns 7200 rpm and does run great when the engine is warm, still some misfire when idling but starts right up and accelerate normal.

when the engine is cold then the problems come back.

 

Are your valves in spec ?

 

i dont know didnt checkt that yet. 365 hours on this machine....
but could be the problems with valve clerance when the engine is cold and runs good when warm ???

 

It's entirely possible. Are there any abnormal noises / ticking ?
Codes ?

 

Hello,

I am new to here. My Friend owns an 2015 570 outlander.

There is one Problem with that ATV.


When you give full throttle from a standstill the engine sometimes stalls. The full power is no longer there and there are misfires. He changed the Spark Plugs, checks the Spark Cables, replaces the Ingnition Coil and one Injector, the one with the easy access. Any ideas what could be the problem here???


THANKS

Belt is slipping

 

well if you hitting the throttle in N position the engine stalles and dies so it has nothing to do with the belt or i am wrong ?

 

I checked today no fault codes. all values like temp etc plausible.
No strange noises

 

i put 2 sets of new OEM Spark Plugs in as i wrote in my first Post.
Water in Fuel is not possible here because after 2 Minutes of riding the ATV runs and starts and idles normal... just some misfires in idling but drives off perfekt.

when u let cool down same things started again.
this Problem is since 6 Month nobody is able to find this Problem i am person 3 now....

 

Well , since everything seems covered , there was a TSB for the G1 bikes years ago that stated a faulty speed sensor can cause the problem you're describing. Not sure if it still applies or if you want to pursue it . Just throwing it out there.

 

Even if the speed sensor is dirty I think that can happen right?

 

Yes ^

 

ok let me check this later today.
but for my understanding... when i´am in N mode....how can an faulty speed sensor do this ?

 

It likely still sends a signal even if that signal is supposed to be "0mph". It's probably worth pulling it out and wiping it off.

 

ok so VSS was dirty i cleaned it but no change...same problem....
OMG it sucks !

why in the world runs it perfect when warm ? what could it be ???

 

I would drain the fuel and put fresh 87 octane, yes 87 not anything else in. Also non ethanol.

Never had trouble with 570s but some of the 850s hate slightly old fuel or 91 octane.

Make sure to get it all out as in the pump sucking the bottom dry not just empty on the guage.

 

well again fuel is like an half year old and it also has nothing to do with that problem, because warm engine run fine then.

I thought at first an bad or two head gaskets because coolant bootle was empty also and maybe coolant gets into the engine and does make those misfires and when the engine is hot it seals because of the expansion block to head, but i made an co test in the coolant which was an negavtive result and ai filled it up and put an hose from the coolant bootle to an empty bootle to check if exhaust pressure gets into the coolant and then overflow it out of the cap but nothing also.

I'm out of ideas at this point and i will give the 570 back to my friend.

 

Seems like swapping the fuel would be easy to try, warmer engines can tolerate more than cold one. But hey it's your choice.

 

You are absolutely wrong about it can't be fuel. Seen many of a time when old fuel would cause a machine not to start. Give it a shot of ether and it would run barely. Then once hot run fine.

Or they start extremely hard and wont idle even with fuel injection till warmed up.

As combustion chamber warms up the fuel burns easier.

I highly doubt its a head gasket. These machines never have head gasket issues. They do loose some coolant. Either from somw of the clamps that leak or the water pump leaks just a little.