Sidewinder power lost after 60 km in trail

[alain langlois]

Good morning all, this is my first treat. I am located in Quebec and i have an interesting problem with my sled.
The firt 40 to 60 km my sleed does have a good acceleration from rest to midrange no hickup.
After 40 to 60 km of riding the engine lost power and backfire when you accelerate, the first few second the engine spool up like normal but after large hesitation, refuse to accel and backfire, does that on repetitive acceleration.
- no codes from the ecm
-no check engine.
- cleanned all sensors lines including turbo intercooler.
- ROV removed and oil tank breather rooted external to keep plumbing cleanned free of oil.
- all turbo clamp checked.
-new spark plugs installed. ( previuos one where ok proper colour)

Suspecting fuel pump, unit removed and filter inspected, look ok. Installed a pressure gauge to monitor the fuel pressure, so far the pressure is within range, approx, 40 psi. The gauge is installed temporary and i am planning a spin tomorow, so i will be able to monitor the pressure during the entire ride.

Do have 10000 km on the sleed.

Any suggestion.

 

[RAMSOMAIR]

My brothers SRX did this last week. It was bad gas. Dumped gas filled with fresh and a half bottle of Seafoam and all good now

 

[alain langlois]

My brothers SRX did this last week. It was bad gas. Dumped gas filled with fresh and a half bottle of Seafoam and all good now

This is my second refill, seafoam added will see if the winder likes it.

 

[mainedrummer]

Seafoam is good, k100 is better.
I add it to all the fuel my sled consumes.

 

[alain langlois]

Thanks for the information, i will keep you informed after tomorow run.

 

[4strokes]

tank vent. loosen cap

 

[jonlafon1]

Fuel is bad. Heet or TORCO. Had this two times in 8600 miles. And your description is EXACTLY what I have seen. Where is the fuel tank level at? Like is it below quarter tank? Mine has done this both times less then quarter. But I still think it’s bad gas/ low octane/water In fuel.

 

[alain langlois]

I installed a pressure gauge to monitor the fuel pump output during today ride. Drove the sleed for 100 km or 60 miles and no problem pressure remained within specification. Shortly after the engine started to have poor acceleration and begin to backfire, the fuel pressure was below 30 psi before this happen, was able to repeat the problem, as soon as the throttle is depress the pressure just fall out.
If I perform a slow acceleration the sleed perform ok but just an extra demand in fuel the power and pressure just fall off.
I tried the sleed with the fuel cap openned and same result.
Only two items can fail in this scenario, fuel pump or pressure regulator.
What are yours best gest on this problem.

 

[KnappAttack]

I'd check the fuel pickups in the tank when level gets low. Something wrong there with fuel pickup. Remove the pump and have a look in the tank making sure pickups are where they belong on the bottom of the tank.

 

[alain langlois]

I'd check the fuel pickups in the tank when level gets low. Something wrong there with fuel pickup. Remove the pump and have a look in the tank making sure pickups are where they belong on the bottom of the tank.

Before today ride I did removed and inspected the pompe inlet filter and ensure that the pickup points were properly located at the bottom of the tank.

 

[KnappAttack]

Before today ride I did removed and inspected the pompe inlet filter and ensure that the pickup points were properly located at the bottom of the tank.

Well somehow it loosing fuel pressure as fuel level gets down. Pump getting weak perhaps? Or sucking air at the pump?

 

[Turboflash]

I installed a pressure gauge to monitor the fuel pump output during today ride. Drove the sleed for 100 km or 60 miles and no problem pressure remained within specification. Shortly after the engine started to have poor acceleration and begin to backfire, the fuel pressure was below 30 psi before this happen, was able to repeat the problem, as soon as the throttle is depress the pressure just fall out.
If I perform a slow acceleration the sleed perform ok but just an extra demand in fuel the power and pressure just fall off.
I tried the sleed with the fuel cap openned and same result.
Only two items can fail in this scenario, fuel pump or pressure regulator.
What are yours best gest on this problem.

View attachment 152989

IMO, usually if a regulator goes bad, it's bad. Since this is intermittent, without more examination, I'd guess fuel pump.

 

[Another Phase]

Mine was doing the same thing except it would act up as soon as the sled was warmed up. It would get worse the longer you drove it. Same exact findings with the fuel pressure falling off. I replaced the fuel pump and pickups and it has been perfect now for 1000 kms. Not sure if ethanol in the fuel is messing with pump internals or somehow plugging the pickups or if it is just pump failure?

 

[alain langlois]

Perfect, glad to hear that I am not alone in this battle, I getting a replacement pump tomorrow.

 

[RAMSOMAIR]

Surprised to hear they are not back ordered lol