My sons polaris predator 50 is bogging down and will eventually kill when under full throttle. I have replaced the plugs and cleaned the air filter but neither seemed to help. It has been about 30 degrees when riding and i know its set for 40 to 80... but hes been riding all winter and only fouled a few plugs. Any ideas would be greatly appreciated.

 

Sounds like maybe a fuel delivery problem? The jets in those things are so small, a little old gas will gum them up very easily. I've cured a similar problem on my sons 06 by running some Chevron Techron in the fuel - its a high rated fuel system cleaner that works.

 

Thats what i am thinking.. I tried adjusting the air and it will run fine but you have to dial the air way down. Its winter so he has ony been able to ride it 3 or 4 times and i just put gas in which means he has had gas in for about 3-4 months and i cant remember if i had a little stable in the gas or not. Any idea if that cleaner works ok with 2 strokes. 04 was the last year they made the 2 strokes.

 

time for an internal carb cleaning

 

Yeah, that cleaner is fine for two strokes. The two strokes are through 2006 - 07 is the four stroke, actually.

 

I had a problem like that with our Polaris 50cc Scrambler (it uses the Chinese engine like a Baja or Eton). It would start and idle fine, for a long time. But when you rode it, it would go about 300 feet at full throttle and stall out. The carb was cleaned, but that never seemed to help. It just felt like it was running out of fuel.

Mine has a flat top gas cap, with no vent hose. That is the key. There is a vent hose that is at the top of the tank and is barely visible if you look down through at the tank through the hole for the handle bars. The open end is stuck into the frame at the top of the left front shock. It was plugged with mud. So it would run a while, until it had a partial vacuum in the tanks, and no fuel would flow.

Cleaning the bit of mud out of the line made it run just fine. It was diagnosed by driving the quad with the gas cap off. It would run fine until you put the cap back on. Shortly after at full speed it would stall.

Look for the flat top gas cap with no vent. If you got one, take it off and run the ATV. If it runs OK, look for that air make up line.