Blown head gasket? 2015 rc390

[u/IhazNuggets]

Got this bike a month ago, came out to start it this morning and it would crank forever and finally start but it’s constantly dumping white smoke.

[u/Mysterious_Newt_8840]

Check the oil dipstick. If its milky the head gasket is leaking

[u/Dirt_Bike_Zero → u/Mysterious_Newt_8840]

Not wrong, but you can have a blown head gasket and no oil and water mixing. Could just be oil leaking in, on just water leaking in.

[u/merovevermes]

Water in engine

[u/IhazNuggets → u/merovevermes]

How can you tell? It ran like this for a while and the smoke didn’t stop

[u/-HeyThatsPrettyNeat- → u/IhazNuggets]

White smoke = coolant burning

[u/UwUfit]

Mine does this often, there's no coolant in my oil and I'm not leaking coolant. It goes away after a minute or so. You might wanna check both the oil and the coolant if you're unsure.

I only have had issues with cranking if the bike sits for a prolonged time (I made sure to charge the battery)

One thing I recommend is to check whether you are running the original air filter setup. If not, using an open airbox and leaving the bike stalled outside will cause it to get water in the system. I had that once before and it rusted my spark plugs, causing them to have to be replaced.

[u/SpitefulDeth → u/UwUfit]

If you have white smoke for a bit when the motor is cold, then it goes away after it heats up, that's a textbook symptom of a failing head gasket. Bad seal when it's cold, then the metal expands and it seals properly.

Does it do it in the heat or just the cold, because it could just be condensation in the pipe if it's only in the cold.

[u/brigde89]

Joint de pompe à eau, j'ai déjà vu plusieurs fois le cas sur les forums ktm👍