[sauce4hire]

I have a 1972 Arctic Cat Cheetah 440 (Kaw motor) replaced the(Walbro-WD carb.) with a (Tillotson-HD). Starts up fine good but when you ride it for about 10min. It starts to die when you let of the gas after running it fairly hard through deep powder. If I pull off the impulse hose leading out of the crankcase and fan the throttle it will go again. Oh yea and this is done while riding the sled. When It dies or I turn it off the motor seams really hot and I also noticed vapor,smoke coming out of the carb. Any questions??

 

[Free Air]

The sooner you put a Mikuni on it, the sooner you will find happiness. Those old pumper carbs almost killed the sport of snowmobiling. If you can arrange a still-air box (silencer box) on the intake, so much the better. Find a carb made for a KAW 440 engine and the jetting will be close. When tuning, start off a little rich on the main jet and then carefully lean it out if you need to. Watch your spark plugs carefully while doing this. A little rich is always better than a little lean...Good Luck!

 

[jsolberg]

Throw on a Mikuni seems to be everyone's answer. Look, these engines were designed to use the Tillotson and Walbro carbs of the day. They ran just fine with them then and mine still do today. If they're kept clean and adjusted properly they are no trouble at all.

My personal experience is that the carb seems to get blamed first for any problem, when ninety percent of the time it is an air leak in the engine seals or gaskets.

 

[sauce4hire]

Thanks guys for you advice and yea it did have a little exhaust leak coming out between the cylinder and exhaust manifold. So I'll replace the gaskets and go from there.