426 Losing Coolant

2 replies to this topic

Posted March 23, 2005 - 07:53 PM


My 2001 yz426 is losing excessive coolant out the overfow hose. I just bought a new radiator cap but I am still losing coolant. The bike isn't overheating though. My FMF pipe runs really close to the radiator, could this be the problem. I have also cleaned the whole system and there wasn't any blockages.

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  • grayracer513

Posted March 24, 2005 - 10:33 AM


If you're losing coolant while sitting at idle, and you're idling longer than about a minute, it's not abnormal. There's no air flow over the radiators, and the circulation within the engine is slowed way down. Try to keep it moving as much as possible. Even just bouncing the revs up a little once in a while will help, but not as much as air on the radiators does.

If the overflow occurs under way, it may be a head gasket leaking into the cooling system, or it may actually be overheating.

  • Dano426

Posted March 24, 2005 - 11:12 AM


Like grayracer513 said keep it moving. I trail ride with my 426 and turn off they bike when waitings for the kids. It also helps to use a coolaint aditive like water wetter or a better coolaint. I am currenlty using engine ice

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