So I just got a 2002 Polaris scrambler 400 4x4 i test drove it and it ran good but it only runs good for about 15 minutes then it bogs out and turns off and won't start back for about 30 minutes of sitting then it'll start right back up and run good for 15 minutes also coolant is going somehere it' not leaking but I have to keep adding ater

 

Have you checked your oil to see if that's where your coolant is going?

 

It' oil injected 2 stroke there is no oil that the water can mix with

 

Sorry. Counterbalance oil. I think it only takes 5 ounces. You really need to keep an eye on it for leaks.

 

No it's not going there I checked

 

If it isn't going out the exhaust it has to be going somewhere. I can't think where else to check for leaks. Maybe if my head quits pounding I can think better. If the radiator is full and all the air has burped out it shouldn't keep going down.

 

Check that the tank and carb vents are open,not blocked or kinked.Check engine compression and also a leak down test on the radiator. Possible it's loosing compression when it gets warm and then dies.Once it's cooled down,metal shrinks and you can run it again for a while. I've see a lot of these when compression was towards the lower end say 100-105 psi. Same thing if the head gasket is leaking.If it's not leaking externally it can be internally and can get into the counter balancer cavity. Pull the c/b dipstick and see if the oil is milky color.

 

So it was blowing white smoke so I changed the head gasket now its not smoking but there is water in the counter alance oil now and it still bogs out after 15 minutes of riding could it be the reeds causing it to bog out and the water pump seal mixing the oil and water

 

So it was blowing white smoke so I changed the head gasket now its not smoking but there is water in the counter balance oil and it still bogs out after 15 minutes of riding could it be the reeds causing it to bog and the water pump seal causing it to mix water and oil also it doesn't idle even if I turn the idle screw in

 

Did you check compression before you replaced the head gasket and also after? That could have a lot to do with it dying after it runs awhile and gets hot. Cylinder could be expanding and the rings(if worn) may lose seal against the cylinder wall. Plus the screw on top of the head has to be bled when ever you replace coolant or trapped air can cause overheating quickly and you can blow another head gasket,warp the head or cylinder if you don't. Coolant in the counter balance is usually from leaking water pump seals.