1986 ATC250r Coolent Problem!!!!

[william16339]

hey guys, i have a 1986 atc 250r that uses coolent.... ive replaced the radiators, i checked over the coolent lines, i REBUILT the enire water pump and i have a new working resivoiur on the back......i have no clue what else it can be, it uses a bit of coolent too....it DOES NOT smoke white or anything... i was thinking its the head gasket, but why? its fairly new....please help- thankyou

[David Ham]

If coolant is down & you are absolutely sue non of your hoses are leeking. It is more than likely a head gasket leak. it could be a rather small league and still run pretty good. One other slight possibity could be a bad radiator cap that is letting a little coolant out while riding but youd probably see the mess if that was the case. I'd double check everything befor pulling the head.

[william16339]

i tried multiple caps, and im absolutelly suree none of the hoses or leaking..i just orded a head gasket now..

[yaegerb]

my guess is the water pump. Perform a pressure test on the water pump just like you would perform a pressure test on the crank case. If I remember correctly it has told hold 8lb's of pressure with no loss over 12 minutes.

[william16339]

I Will try, but as stated, the water pump is fully rebuilt...

[RIDE-RED 250r]

I Will try, but as stated, the water pump is fully rebuilt...

Including both seals??

Does the transmission oil look good? No sign of antifreeze getting into it?

[Marty]

I personally would do a leak down on coolant system better to be safe than sorry!
But if you plan to put on a new head gasket make sure to use only OEM head gasket and have head checked for squareness!
Anytime I do a top end I always have those deck checked and squared. But over time with those cold and hot cycles you would be amazed at warpage those heads endure. And if money is no object buy new head bolts as well it is just cheap insurance.