2016 yz450f colant in oil

[Levi Patzer]

I have a 2016 yz 450 with only 40hs on the bike, I brought it out the other day for a ride, after I realized the bike was running hot and I check the oil and was full off water. After i checked it out, just about all of my colant has got into my oil, any ideas of where this is getting in?

[deweym21]

It might be a blown head gasket.  Which would be best case scenario.  If it is not there's a chance that you have a cracked head, or less likely damaged cylinder.  Either way it's time for a top-end tear down to investigate.  Make sure and check for warpage on the head and cylinder surface to make sure that they mate together.   If you don't have any experience doing any of that, better take it to a shop and have them do it.

[SteveThe Snakes]

If it’s been apart someone didn’t torque the head bolts per the manual. Also do not run any more than 50% water as it will boil out and overheat the head and ruin the top end. 

[Yami4daddy]

On 4/17/2019 at 12:14 PM, StevetheSnake said:

If it’s been apart someone didn’t torque the head bolts per the manual. Also do not run any more than 50% water as it will boil out and overheat the head and ruin the top end. 

Not entirely true. Running ethylene glycol at 50% vs lets say 30% only raises the boiling point 5 degrees. Ethylene glycol,  or even propylene glycol,  isnt the major factor in raising boil point, pressure is (1.1 bar or 16psi for our stock systems). Rule of thumb you gain about 2.5 degrees for every pound of pressure. So running 30% EG to 70% water with the stock pressure cap will yeild about a 260 degree boil over, 50/50 EG and water will yeild 265 degree boil over.

Also note, the more water ran in the cooling system the more efficient the cooling system will be at getting rid of heat. Water is by far the best liquid for heat absorption and shedding heat. So all things equal, a system at 70% water 30% EG will run cooler than a system at 50% water 50% EG. Throw in a water wetting agent and the benefits of water are even more pronounced.  

Your climate and use should dictate what and how much EG/PG to use in your system. You cant go wrong with 50/50 mix, but there are benefits to running more water. Some racers even running 100% water and a water wetting agent like redlines "water wetter". If you do go the "more water route", I would suggests atleast a small percentage of antifreeze (EG/PG) or a water wetter for its anti corrosion and lubrication properties.  

Ive included a chart for reference but research your ratio and see if it works within your climate that you operate in. 

[SteveThe Snakes]

6 hours ago, Yami4daddy said:

Not entirely true. Running ethylene glycol at 50% vs lets say 30% only raises the boiling point 5 degrees. Ethylene glycol,  or even propylene glycol,  isnt the major factor in raising boil point, pressure is (1.1 bar or 16psi for our stock systems). Rule of thumb you gain about 2.5 degrees for every pound of pressure. So running 30% EG to 70% water with the stock pressure cap will yeild about a 260 degree boil over, 50/50 EG and water will yeild 265 degree boil over.

Also note, the more water ran in the cooling system the more efficient the cooling system will be at getting rid of heat. Water is by far the best liquid for heat absorption and shedding heat. So all things equal, a system at 70% water 30% EG will run cooler than a system at 50% water 50% EG. Throw in a water wetting agent and the benefits of water are even more pronounced.  

Your climate and use should dictate what and how much EG/PG to use in your system. You cant go wrong with 50/50 mix, but there are benefits to running more water. Some racers even running 100% water and a water wetting agent like redlines "water wetter". If you do go the "more water route", I would suggests atleast a small percentage of antifreeze (EG/PG) or a water wetter for its anti corrosion and lubrication properties.  

Ive included a chart for reference but research your ratio and see if it works within your climate that you operate in. 

Well I run 100% out here in So Cal and yes that’s 387 degree boiling point. Anything else is a boil over where we ride. 

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