M7 dropping cylinder

[rigrat]

Took both reed cages out of engine and did an inspection, everything looks perfect. Since i am testing sled at lower elevation than we ride could efi be overcompensating and running rich enough to be overloading one cylinder. Noticed my 08 m1000 seems to load up a lot more often when ditch banging at lower elevation and my brother 08 m1000sp loads up a little more than mine.

 

[swabby]

if TPS sensor is not working the sled would probly not even start , i would recomend checking the reads again realy thorough, rigrat chances are if junk was caught up inthe cage even the smallest minute scratch or chip will cause a puddle or drip effect in the intake we had that last season on buddys zrt we pulled the reads like 3or 4 times be4 we found a minute chip on the peddle we replaced the read in question and all was good, when pulling reeds was the intake between efi and engine realy wet?

 

[rigrat]

Pulled both reed cages again this morning and they both look good, all the reed petals appear to be in excellent condition and all are sealing to the cage as well. When looking into the airbox side of injector bodies it sure looks like there is quite a lot of fuel and oil. This is why i asked if sled could be running overly rich for some reason? I will check the part # of the sensor in the airbox and see if it is the same as the one in my m1000. If it is i will do a swap to see if it does anything. I still need to find out what the fuel pressure should be and check it. Thanks for all of the help guys.

 

[Demon13]

I would pull your power valve and make sure that it is opening all the way because the power valves only open at higher rpm maybe one is gummed up and sticking.

 

[rigrat]

Already checked the powervalves and everything seemed to be ok. Sled only has 300 km on it. I still plan on lifting back of sled off of ground and checking operation of powervalve servo at rpm. The powervalve servo operates freely by hand and cables are good. The powervalves appear to work fine when i view them through the y pipe. Thanks.

 

[rigrat]

Merry Christmas everyone. Had some time to lift sled off of the ground and check operation of powervalves at rpm, everything looks good and valves seem to open at 7000+ rpm. May have to take it in to a dealer. Any recommendations on an arctic cat dealership with a good service dept around the Southern Alberta area? Thanks.

 

[HagmanMod1]

i had my tps sensor buger up on my rev and it made the rave valves work backwards sled would still run good at wot

 

[rigrat]

Weather warmed up here so i thought i would take sled out and do a little more testing (at our low elevation). Filled up with new fuel and found that sled is running better but not great (will still drop a cylinder at times). Put about an hour on it and then pulled the plugs again. Both plugs now look damp and it sure seems like sled is overcompensating for the low elevation and is running too rich but there is not a lot of smoke. Have not had a chance to check fuel pressure yet. Could the problem be too much fuel pressure? I still need to know which arctic cat dealer has a good service dept around southern alberta or southeast bc, how about a couple of recommendations.Thanks.

 

[RUDY]

Rigrat,this sounds close to what mine is doing as well.I Thought maybe i got a piece of ice in the lines or something but it the sled ran fine for 20 miles then started acting up like yours....Sound ok at idle hit he gas,BANG down to one.
I was gonna try to throw a pile of heat on it to see if it was iced up or something,but i deceided to just take it to the dealer.I'll know more on it on Mon. or Tue....I can let you know what they tell me.

 

[rigrat]

I would sure appreciate it Welder. I read in another thread that the rubber accordion hose between the hood and airbox could be collapsing, cutting off air to motor. Think i will pull mine off and see what happens. I also previously put mine inside the heated garage and mixed in some gas line antifreeze. Never helped at all, in fact sled was running worse than ever. Plug gap was a little wide so i closed it up to 028, no difference. Thanks for all of the previous ideas everyone.

 

[RUDY]

what plugs are you using right now in it?I have BR9EYA i believe

 

[rigrat]

Mine are the same (stock) and i have tried two sets,no difference.

 

[I'vegotthenutz]

I would check to make sure your spark plug wires are actually making contact with the boot. I just found a spark plug wire disconnected from the boot on my new sled, plugged it back together and it ran great, exactly same symptoms your describing

 

[calgarysledguy]

This came of of snowest.. Maybe it will help i dont know. I have had a few times were the snow or water gets in there. Maybe its over or under compensating for something. I dont know something i have played with when i get a bog.


(I have been struggling with a low to mid range bog for a year and a half. I finally figured it out yesterday. The clear plastic tube that comes out of the ECU was routed wrong. I had it routed so it pointed down in the bottom of my belly pan. While riding yesterday. I was pissed off and tired of the sled so I stopped and opened the hood to check things over. My friend look at that tube and said try routing that tube a different direction. So I routed it along the main wiring harness back towards the fuel tank. Closed the hood started the sled and punched the throttle, it was like someone flipped a switch. The sled ran totally different, it ripped all day long. THE BOG IS GONE!!!!! If anyone is curious I have a Injector perfector, a "Thing" can, and a RK-Tek secondary installed. So if you have a bog check the routing of that plastic tube. Good luck. )


Hope this might help

 

[rigrat]

Will reroute the tube like you mentioned and give it a try within the next couple of hours. Also my 08 M1000 has the tube routed down towards the belly pan and it runs fine.

 

[RUDY]

what is the clear tube for?
Is it possible that it got blocked up with ice or snow?

 

[rigrat]

Rerouted clear tube from ecu and checked rubber banjo tube between air box and hood, no improvement. Starts great, Idles great Part throttle ok, Crack it open and it runs like ch!t.

 

[calgarysledguy]

Rerouted clear tube from ecu and checked rubber banjo tube between air box and hood, no improvement. Starts great, Idles great Part throttle ok, Crack it open and it runs like ch!t.

That sucks hummm

 

[RUDY]

this is crazy,i've never heard of trouble like this and no one can figure it out.Is there a flaw that Cat should be looking at or what?
Honestly a guy spends how much money on a sled then it acts up and nobody can seem to figure it out,crazy.
Well i hope they can at te dealership tomorrow or Tue.

 

[M7Plus]

if you talk to your dealer ask them about any up dates or flashes for your ecm. I know that there is updates for the ecm with a square on them and i dont know about the other two ecm's. My m7 has a low end bog and from what i have been told this up date should fix it.