Need the M7 Experts on this one!

[Killerk]

A lot of posibilities have been thrown out there.

When was the last time you cleaned your powervalves, and how often do you clean them?
The reason I ask is because with the amount of miles you have, they should have been cleaned multiple times by now... And the fact that you are unsure of how to inspect the power valve cables leads me to beleive you have not cleaned them?
This is the forst place I would check... If they stick, or if a cable pops off, they will idle fine and run fine just above idle, then fall on its face.
I had a similar "intermitant" problem on my F-7... Turns out, the head of the allen bolt that holds the valve to the cable had broken off... The head of the bolt couldn't go anywhere, but would move around and cause the valve to not fully close at times... Replaced the bolt and it ran great.
My buddies did a similar thing and was throwing the cable off the servo... His had very carboned up power valves.

 

[kraftymike]

Here is where I stand as of today. Fuel pick-ups clean. Power Valves were deffinatley carboned up but now clean. Servo motor cables attached and actuates free manualy. Put my ECU on my buddies sled today ran good so I can rule that out. Sled idols well and will pick up for 10 seconds so I don't think reeds are the problem. That leaves me with I am guessing either a coil or sensor issue. The problem only occurs when hot. Coil sparks cold any ideas how I can test my coil in a hot condition? Any suggestions or corrections in my analysis would be much appreciated.

 

[76FOMOCO]

if you have a buddy you can change ecu's with change coils with him also, and pull plugs and check to see if wet or lean. this will help us help U

 

[T&A1000]

I have an 07 m1000 doing something similar. When it is cool it runs great but after a minute or two it starts to miss really bad if I go above 3/4 throttle. Not sure what is wrong. If you figure it out I would like to know what you did to fix it.

 

[m8magicandmystery]

if needing to simulate a hot condition for coil or sensor just place a trouble light close to the item you want to check...

 

[Stanowski]

Sorry i didnt bother reading everyones posts but by reading yours im willing to bet on your throttle positioning sencor located at the end of your throttle bodies, there is no way to test these, they can run good for up to 20minutes before they fall flat on their face or they can run 2 secconds or sometimes they will not run at all, so if you test it, it could be working while you test it, but 30 secconds later its dead again.

 

[Neckcitymt]

Im having the exact same issue as kraftymike explained, on the same sled. Has anyone heard of a solution to this issue? Or where kraftymike left off?

 

[Sledbrain2]

I would send him a pm in hopes he is still on here, I have a 06 m7, had stator go bad at 1700 miles and a crank sensor go bad that gave me similar issue as this thread. The stator just went bad all of a sudden(went to start in august no spark, re-wound stator fired right up)

You can check the tps with a home made tester with some alligator clips. That can also give you similar issues. It is a major pita to get at it to test, but if you are going to pull throttle body to inspect reeds would be the time to test it.

 

[Sledbrain2]

how to test and set tps

Here is my home made tester to set a tps, have to find the minimum and maximum for voltage values for each model to test and set. I set my M7 to .68

https://youtu.be/s2Kscnzr5ow

 

[Jonathanpitzl]

I have had 2 m-series with the same problem. turned out to be the can that was on both of them. They would run great for 1 or maybe 2 pulls then have the same burbling issue as yours. and when I sat for a little bit and started it, it would run good for 1 pull. I didn't talk long for the can to be worn out either. My buddy got maybe 500 miles on his sno-stuff rumble pack can then it was shot.
Also this year on my m7 I had a hand warmer grounding out on my handlebars causing it to burble and gauge have issues. unplugged them and go to go

 

[Neckcitymt]

I tried the pm, hopefully hear from him soon. Thanks for the tips on the tps, i may go that route eventually however feel something else is at play.

The sled is new to me this year, and i am learning my way around. A couple weeks ago my check engine light came on, however i missed the number of flashes, so i wasnt able to determine the code. I originally thought servo motor, so i cleaned my power valves and checked the cables. My valves had a bunch of residue on them; i soaked them and got them nice and clean. At the same time i changed the plugs and noticed discrepancies between the color of each plug. The fresh plugs made a huge difference from idle to its peak revs at 6500, where it would stay for a short time before dropping down to 5500 and staying there or lower. If i turn my sled off, and start it back up, she always has good power for the first rev (and sound good), but then drop back down to 5500 (with weird rattle).

Today i spun the track to confirm that my revs were not high enough to kick in the servo. I then pulled my plugs and confirmed discrepancies in color of plugs. I then pulled my y pipe and took a look into the cylinders. The cylinder walls looked unmarred, and the y pipe sides of the pistons looked good as well. I plan to test the compression tomorrow. Additionally, i took a look at my clutch to make sure everything was working smoothly. I think i may look into the reeds next, ill post back.


Any body ever have any fuel pump/pressure issues on these m7's?

I have heard of similar symptoms due to out of wack fuel pressure..

 

[Sledbrain2]

Your peak rpm should be 7800 to 7900, could just be a broken spring in primary, I would pull clutch or at least pull the cover an inspect spring, rollers, and how much play on shaft. Putting cover back on use a torque wrench, 12 lbs on bolts.

Do you get any back fire? Back fire would indicate something with ignition, TPS issue will be very erratic rpm will jump up and down when you hold the throttle steady.

Reeds could be an issue, but I believe that is lower in the rpm once you get on the pipe the motor should rev like normal.

I would get your clutching in order before you go any further.

Your check engine light was probably from the engine getting too hot, it will flash then, stay on, last is engine will go into limp mode if you do not get into fresh snow.

 

[Neckcitymt]

i thought the spring on primary looked ok, but I may have overlooked something. What should I be looking for?

 

[Sledbrain2]

it could be broken, if its original I am pretty sure its sacked out, I would replace it not matter what, they are like 20.00 and you will be amazed how much different the sled will pull with a new spring. There should be two colors of the spring unless its a titanium(usually a solid color and stripe). Also use a punch to mark both the cover and a tower so you can place the cover on the same way it came off.

 

[coolm7cat]

My m7 would run like crap when I got on the throttle puff out black smoke. Then go into limp mode. I changed plugs and it would run alright for awhile then go back into limp mode. Tried everything suggested here. Even tried new gauges nothing worked. Took it to the dealer they tested all the electrical and couldn't find the problem. They had my sled for 3 months calling arctic cat to help with this issue. Finally they found the problem it was my stator and my ignition timing sensor was bad. Replaced it with a new one and the sled ran great. This was 4 years ago at that time it had about 1500 miles on it. To date that sled still rips. Hope my experience helps you out.

 

[coolm7cat]

Here is what they did.

 

[Neckcitymt]

coolm7cat, thanks for the list of items. Im going to test compression tonight and get back to you guys, hopefully it goes well. Here is what i have checked so far..

Good Spark
cleaned power valves
changed DD oil
checked power valve cable attachment to servo
Checked oil adjustment rod, oil pump spring was gunked up, now clean and functioning
pulled plugs, one is darker than other (checking compression tonight)
checked my clear tubing out of air box, all looks fine

I plan to test TPS soon, what should multimeter read?

 

[Neckcitymt]

sledbrainb2,

No backfiring of any kind, ill look into clutch components soon

 

[Sledbrain2]

my m7 tps read .68 at idle when I check it,

 

[Neckcitymt]

Compression read a hair under 120/120

Something i forgot to mention was that the previous owner put an after market can on her...