1996 Arctic Cat Cougar 550 Strange problem

I just got this sled about a month ago, after the first snow I fired it up and went for a short ride, seemed to run okay but it was a bit boggy, I just thought maybe old gas, drained the gas tank. Week later went for another short ride, started good, idled good, but not long into my ride it started to bog down again and a few times it seemed like the engine cut out altogether, I had to keep pumping the thottle and useing the choke to get it back to my house, not long after I got it back to my house it died and would not start again, took it into a nice heated building let it sit for a few hours and it fired right up again, okay I thought maybe just moisture in the fuel system, added gasline antifreeze, also a friend of mine who works on snowmobiles was there so he checked the fuel pump, cleaned the carbs, changed a few gas lines, checked the engine compression, checked for good spark all seemed good.
Took the sled back to my house, unloaded it, fired it up, idled good, about a 1/4 mile into my ride it started doing the same thing as before eventually stalling and now it wont start again. I took out the spark plugs and put a little gas in each cylinder, put the plugs back in and tried starting it , it did fire but as soon as the gas I put in cylinders was burned up it quit. Any ideas on what to try next because I'm out ideas.

Vent on the gas tank is plugged it will starve for fuel , coil is on it's way out , try these two things , loosen fuel cap take it for a ride , still acts up borrow a coil all the old cat coils will work

I had a similar problem with a 93' Lynx, so we replaced all the fuel lines under the hood and it fix that problem, one of them must of had a slight crack in it.
I also had a 99' powder special and it would run great until you got going then it would bog and feel gutless, so after I replaced the coil and bypassed the safety shut-off switch in the throttle lever it still would bog. So I replaced the air silencer (the part between the carbs and the air box.) since it had a small crack in it. and it runs much better now. (I also replaced all the fuel lines in it when I rebuilt it too.)

Like Trollcat said, try the vent line for the fuel tank and go from there.


Best of luck.
B85

Lesson learned, it turned out there was actually ice in the bottom of the fuel tank and the antifreeze I put in just wouldn't take care of it, we siphoned out as much gas as we could then took the gas tank off and dumped out the rest of the gas, waited for the ice to melt then dumped out the water, it was like a sheet of ice frozen to the bottom of the gas tank, not sure how so much water got in there but the sled has ran great since we got rid of the water obviously.