Low end bog

[jjacobs]

I have an 2004 arctic cat 900 EFI mountain cat. I had a ECU problem this summer and ended up replacing the ECU, stator, ignition everything and know i have developed a low end bog. It bogs really bad when i start out or anytime i let off from full throttle. If i can get it above 5000 it runs awesome. I have also cleaned and put new power valves on it. i am running out of ideas and the local shop is scratching there head. I saw your web page and was wondering if you had any ideas for a solutions. Thanks.

 

[Tmann]

Have you cleaned your injectors and checked all wiring to ensure its good and grounded.

 

[bigborecatdragon]

Try and pull the tps plug off the throttle bodies. If it bogs with the plug off then have someone dial your crank. It needs to be tdc 180 opposite . If your crank started walkin on ya then it would explaine that nothin fixed it.Doesnt normally happen to the 9'z but it can.Blown belt or dry clutch slam can pop the lobes just enough to make ya go nuts tryin to figure out whats wrong.I would disassemble the thing and make sure the transfers were lookin normal.If part of the piston skirt is gone then it over fuel on the bottom end(Like a window port).The guy in estacada with the dragon dilemma.

 

[bigborecatdragon]

also could under fuel causing lean bog.check pistons

 

[diggerdown]

Do you have an aftermarket can on it? It is very common for a can to cause a bog at one elevation and run clean at another. ECU's seem to vary for some reason and what works for one does not work for the next one that is supposed to be the same. I've got my own issues with a M8 and have checked and tried about everything to resolve it, no luck yet! I also have a sled like yours with a mbrp can that bogs bad a low elevation and gets progressively better as I go up in elevation, I know thats the can.