m7 backfires when under throttle engine light flashes

Ken Climb · Feb 24, 2008

It just started doing this toward the end of my ride today. Anything over 1/4 throttle and the sled does a pulsing hesitation wha wha wha wha thing then if you punch it it starts to backfire. Engine light also comes on when backfiring (flashes when backfiring)

Wierd huh! Its never done this before, and the only thing I've done to it lately was put on a rkt 13.5:1 head. I was hitting some jumps etc, I don't know, maybe knocked some wire loose? I'm new to a/c sleds. Thanks in advance for any suggestions! K.L.

Ken Climb · Feb 24, 2008

ttt nobody?

m8magicandmystery · Feb 24, 2008

weird...did you add fuel near the end of the day...from a jerry can etc...just wondering if you introduced bad fuel or possibly diesal into your sled somehow...another thing to look at is your sparkplug boots etc..arcing.. grounding..etc..and throttle position sensor needs to be possibly bypassed to see if problem and maybe powervalve cable broken..??..just some quick thoughts and suggestions

bluebear · Feb 24, 2008

Did you happen to catch what sequence the light was flashing?

What you've got kinda sounds like a TPS problem.

Chris.

speeddemon · Feb 24, 2008

My TPS went out and acted like that then blew up!! have it checked
mike

Dobber1 · Feb 25, 2008

Check to make sure the throttle cable returns all the way back to the throttle stop position.

Ken Climb · Feb 25, 2008

Going into the local a/c dealer tomorrow. I'll get them to check the above ^^

Thanks, Keep'm coming!:beer;

bigb55 · Feb 25, 2008

sounds like the stator is going out mine did the same thing on and off for a couple of rides then just quit

Ken Climb · Feb 27, 2008

Bummer ,my a/c dealers too busy this week!

mrquick68 · Feb 27, 2008

Do you have a can on the sled Ken? If so, switch back to stock. The different back pressure compared to stock kills wacks out the EFI and makes the bog, usually no check engine light though.

If its not the can, and you can try to catch the sequence of the check engine light, you can look under the hood at the sticker to see what the problem is. I would venture a guess that if its not an aftermarket can, then its your air temp sensor, sometimes they over heat and throw your sled into limp mode. This is also an easy fix. Make sure the wires are connected properly, put on some dielectric grease on the connection (blue plug), and then goes as far as moving the location of the sensor to the far right of the box to keep it way from the pipe. The pipe is too close to the sensor and can cause the sensor to overheat, which sends the sled into limp mode (that's why the new 1000s and 800s have a shield under the pipe.)

Hope this helps.

Ken Climb · Feb 27, 2008

Stock can......Thats what it seems like, some sort of limp mode. So will your engine light flash and your sled back fire when in this limp mode? At 1/4 throttle its starts the hesitation wa wa wa wa thing then when you apply a little more throttle th ewa wa wa turns into bang bang bang (backfiring) and as it backfires the negines light blinks (approx the same time). Does this sound like limp mode?

And where is this sensor located exactly in the stock airbox ducting? I know you said blue connector.
I haven't tried the sled since it did this.This is the second tme now it did it but this last time it didn't snap out of it(unlik eth efirst time)both times were near the end of my ride and after jumping etc. I'll go try it know and see if it does this amd di-electric grease all my connections and locate and maybe move the temp air sensor.

mrquick68 · Feb 27, 2008

It sounds fairly similar to the problems i have had too. Near the end of the day, everything is good and heat soaked, usually happened after i stuffed the front in deep in the snow after jumping or coming down from a wheelie... Sounds like yours...

The air temp sensor is located right in front of the pipe in the "black box" that occupies the entire nose cone. It has a black and blue wire coming out of it and goes right into the ECU which is bolted right above it. Pop out the sensor, make not of the sizes of the three holes, copy the pattern, and then remount sensor on the flat vertical portion of the air box near front righ shock well. Hope this makes sense and helps. Before you go this effort though, it would be nice to know which code the ECU was flashing.

Ken Climb · Feb 27, 2008

I went through all my connections w-deed them still does it! theres no sequence to th eenging light it just comes on and off when the sled backfires and it backfires after 1/4 throttle and higher.1/4 and below it just kind of hestitates( jerks on and off like I said kind of a wa........wa .....wa........wa....wa.....then if I apply any more throttle it turns to backfires

mrquick68 · Feb 27, 2008

Ken Climb said:
I went through all my connections w-deed them still does it! theres no sequence to th eenging light it just comes on and off when the sled backfires and it backfires after 1/4 throttle and higher.1/4 and below it just kind of hestitates( jerks on and off like I said kind of a wa........wa .....wa........wa....wa.....then if I apply any more throttle it turns to backfires

OK next trick - possible the safety switch in the throttle assembly. These have been known to break and do similar things. Follow the wires from the flipper down behind the alum. plate on the steering post support. I think the plug has brown and purple wires, unplug it. You'll have to use the key to turn the sled on and off instead of the kill switch though. Just try it and let us know.

Ken Climb · Feb 27, 2008

I unpluged one set there and she won't fire....wrong one I guess but the only oset visible. How do I know which set of wires? This sucks!

mrquick68 · Feb 28, 2008

Ken Climb said:
I unpluged one set there and she won't fire....wrong one I guess but the only oset visible. How do I know which set of wires? This sucks!

There's only a few sets of wires that come from the throttle side (thumb warmer switch, hand warmer, thumb warmer, and then the saftey switch. You'll you know you've found it when your sled will start, but won't turn off with the kill switch.

KERBY · Feb 28, 2008

Throttle

My Buddy Had This Happen. He Was In A Lot Of Deep Snow Let It Sit For A While Started It Up And It Did The Same Thing. Had To Pull Him Back Took It In A Warm Shop And Never Did It Again. The Throttle Was Froze Enough To Make It Think The Throttle Was Stuck . Just An Idea

mrquick68 · Feb 28, 2008

KERBY said:
My Buddy Had This Happen. He Was In A Lot Of Deep Snow Let It Sit For A While Started It Up And It Did The Same Thing. Had To Pull Him Back Took It In A Warm Shop And Never Did It Again. The Throttle Was Froze Enough To Make It Think The Throttle Was Stuck . Just An Idea

Yep - just unplug the throttle safety switch next time as i've talked about above to get home

.

bushy · Feb 28, 2008

Is it a sharp noted backfire (piston) or a duller boom (pipe fire). Fuel pressure may be too high causing flooding. I doubt it.. Plugs wet? Stock or fuel mods? Crank shaft positions sensor fouling up timing? Good luck. I hate tracking down bugs. It's usually something obvious and simple.

trencher · Feb 29, 2008

Heard of this problem. Check wires under seat for bare wires. Don't know if m7's have a fuse.I burned a fuse on my m1000 it ran in limp mode. Hope this helps.

m7 backfires when under throttle engine light flashes

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

New member

Similar threads