i have a xplorer and i am noticing bubbles out of my cooling system. i noticed that the t coolant was low and filled it and it ended up missing again. i just had the jug and head machined and put new gaskets on. still does it. i was wondering if there are any other places air can get into the cooling system.

 

You have to bleed the 10 mm screw on top of the head or air will be trapped causing problems. Loosen the screw at the back of the head,allow coolant to flow out along with any trapped air,then tighten. I've had several customers not do this and if run long enough can damage the new top end plus can warp the head from over heating. OPT

 

well i went out today and tried top blead the air out. loosened the screw and coolant but no air that i saw came out. i did notice that when i was running it for the first couple minutes no air was coming out. than it happened... small (i mean really small) stream of consistant bubbles started rising. i was wondering if the water pump could in any way be the culprit. cause i know that the crank case gets pressureized too on a 2 stroke. what are your thoughts?

 

Just trapped air pocket! Thats why its important to bleed head until nothing but coolant is flowing out with NO bubbles. OPT

 

i replaced the head gasket last year in the fall. than get it back cause the coolant was low again and the resivore was completely empty. i know that the coolant was full and all the air was out last year. now this time i resurfaced the head and jug along with a new head gasket. and i am postitve that i have ran it enough and cracked that bleeder screw to get all the air out. the bubbles are very fine and it seems as if there is an oil film at the top. i have a funnel inserted where the rad cap goes on and filled about half way to see the bubbles and the oil foam rise to the top. so im positive that all the air is out. what do you have in mind next? thanks

 

If you have an oil film from the coolant its possible the gasket is leaking or the cylinder or head could be slightly warped. When you resurface its best to do/check both the head and the cylinder. Just from my own experience. OPT

 

i resurfaced both the head and the jug. with a new gasket. is that the only place that air could be entering the cooling system? what about the crank area? can the pressure that is built up in the crank from the downward stroke put pressure through the oil seals on the water pump? or is the counter ballance shaft a seperate and sealed section from the crank area

 

IMO,You need to pressure check your cooling system and radiator cap. My 400L has a 13 psi cap so should be tested at that value. If you have air entering the system the pressure test will put coolant there so, beware of it possibly entering the combustion chamber. If you can't see where the leak is it is most likely internal. Just watch the pressure guage to see if it falls.

 

check the oil in the counterbalancer and see if any traces of coolant are in there.

 

ok i will try to pressure test it. i have a tester here at work and can give that a go. but im confident that the head gasket and surfaces are fine. cause i tested them before i sent them out. but also air is thinner than water and the combustion chamber compresses more than 13lbs at that head gasket. and my bubbles dont look like im blowing through a straw. they are finer bubbles than the bubbles in a soda. and i will check the counterballance dip stick. i found diagrams online of the exploded view and thought everything was lubed with the 2 stroke mix that was sucked in...