2 of 3 cylinders firing - Snowmobile Forum: Your #1 Snowmobile Forum

thundercat 900 · 11-22-2012, 07:56 PM

Hi everyone,
I have a 1996 Thundercat 900 and i noticed the other day when i started it that the left cylinder (if you are sitting on the seat) is not getting hot while the others are. I just checked the spark and its the same as the two good cylinders. No cuts in the plug wires from what i can see. And i checked the compression and all 3 have the same around 140-150psi. My only other guess is if the carb is gummed up. I just wanted to see if anyone had any opinions. Taking the carbs off is a pain in the A** on this so if i can avoid that i would be much happier.

Any help is appreciated
Thanks

Kemo · 11-22-2012, 08:22 PM

I would tear into the carbs annually. Pull the spark plug, give it (the cylinder) a mixture of fuel and oil. If it fires, you definitely have a fuel delivery issue. Regardless, I would clean ALL of the carbs. It is a lot easier to clean those, also a lot cheaper than rebuilding the engine. Laziness is extremely expensive.

**kccats** · 11-23-2012, 07:21 AM

Pull the carbs, remove the air box! Get a SLP air box! One wing nut and a small bungie and it's off! Go threw the carbs! Pay attention to the pilot jet (Up the tube)! If not you really can melt down a piston!

thundercat 900 · 11-23-2012, 10:18 AM

Thanks guys. Im going to take the carbs off now and clean them up. Hopefully its that simple.

Blaine1 · 11-24-2012, 07:26 AM

Could also be spark related...when a stator starts to go bad it will cause the condition you described. Your stator ohms are 450 and 25. If your low speed coil reads higher than 450...it is bad.

Testing a stator in a snowmobile Arctic cat - YouTube

thundercat 900 · 11-26-2012, 11:34 AM

Well i cleaned the carbs and it seems like that worked because the cylinder is now getting hot. But ill still check the stator since the video shows it as an quick check just to be sure.
Thanks for the help.

**kccats** · 11-26-2012, 01:30 PM

Every Preseason!