2015 Rancher Backfires then Dies

[GlacierRunner 0]

I bought my 2015 Rancher new, it has never had any issues. About 400 easy miles. It had been sitting for 3 months but I put in a new OEM battery, air filter, oil, and oil filter to prepare for riding season. Ran it for the for the first time and idled it for about 15 minutes, it ran perfectly. I tried to drive it down the trail and it backfired LOUDLY then sputtered and died after like 2 minutes of acceleration. It starts back up after a few seconds and idles for days. But as soon as you put it under load it dies after about 30 seconds.

A KTM mechanic was at the trail and told me he thinks it's a fuel delivery issue. The fuel pump seems ok since I can hear it spool up when I turn the ignition on. I replaced the fuel filter tonight (WHAT A PITA) and it didn't help at all. Didn't notice any particulates in the tank. Going to get a new spark plug tomorrow. Any other ideas?

It did have about 3/4 tank gas when I put it away and I forgot to use Stabil. I added 1/4 tank of new gas. Could it be the fuel? Could it be the fuel pump even though I hear it turning on?

Thanks!
Cimmy

[shadetree 5,977]

dump the tank of fuel, sitting for 3 months is a no no when you do not run it..or treat the fuel ?. alot of the ranchers with fuel pumps have/had defective fuel pumps..not saying yours is one of them ?, but keep this in mind. it is fuel injected..could also be a dirty fuel injector ?. never..ever..let them sit that long without running them ?, or treating the fuel for long storage ?. you say it idles fine..but dies under a load ?, i'd say the fuel pump or dirty fuel injector is where i'd look.

[Fishfiles 20,147]

I would think it is a fuel problem , I think  your pump is in the tank , older ones are  in a  seperate fuel filter housing ------  there is a  recall on the fuel pumps for certain years , not sure if yours is in the years 

[GlacierRunner 0]

Thanks for the replies. I always treat my fuel but I totally forgot this year. Saw the full bottle of Stabil on my shelf and kicked myself. I'll drain the tank tonight and fill it back up with premium along with some SeaFoam. If that doesn't work it's on to the fuel pump I guess... Does that sound like a good plan to you guys?

[Fishfiles 20,147]

Bummer , it is 2019 and up on the fuel pump recall 

 

[jeepwm69 7,751]

Check your pump, filter, injector.

 

I've had bad fuel pumps, but one was actually a clogged injector.

 

 

 

This guy it was the fuel pump

 

 

If you let the EFI machines sit with ethanol gas in there, it will gum up and kill the fuel pump.

 

Take the injector off, pull it off the line, and see if the line sprays gas everywhere when you turn the key on (priming shot).  If it does, probably a clogged injector.  If you don't get gas then it's probably your fuel pump

 

 

[toodeep 1,760]

I would start with the spark plug first. Most likely it's going to fix it. I don't use stabil in any of my machines and even with today's gas I'm not afraid to let it sit for 3 months or longer.

[Tdog 1]

I know this thread is over a year old, but in case helpful for others like it was for me. TooDeep was exactly right in my case: spark plug replacement cleared up the issue.  It was moderately carbon fouled. Maybe that's expected given I mostly run it for short trips/low speeds.  I need to get on that thing more!