Tech Tip 7 Hidden Damage from playing submarine

Everybody loves to run through the water, especially to splash your riding buddies. But what happens when you get in a little “over your head”? You drown out and have to wade to shore! Now what? You know the drill. Drain the carb, airbox and check for water in the crankcase.

If your oil was milky then repeatedly changing the oil will remove all the water, right? If not then engine heat will eventually evaporate the rest of the water, right? No & NO! There are places in an ATV motor where oil flow is marginal and the exterior cases are cooled to an extent that water constantly is formed from condensation (Remove the starter gear cover of any Honda 300 4×4 used for plowing and you will see what I mean). Add in pure swamp water and you have a frothy mess that is most difficult to get out.

A little water with all that oil can’t hurt anything right? Guess again! Needle bearings are a magnet for water laden oil, it gets in and “it don’t get out”! And the water will damage more than just the needlebearing. Why? A ball bearing rides in its own self contained race. Whereas a needlebearing rides directly on a shaft. So? Check out the pic of an ordinary output shaft and its needle bearing. Notice anything unusual? Zoom closer. Notice the discoloration of the shafts race? How about the blue tinge inside the needlebearing. Know what blue metal means? The temper is gone. That metal now has the tensile strength of dry Silly Putty! Lets go closer. Now you can really see the damage.

ALL of that damage was cause by water laying in that needlebearing for an extended period of time. Over the course of that period of time there were oil changes but the water was not flushed out due to the design of the bearing as well as the propensity of water to bead in relatively cool areas of the crankcase. Without sufficient heat that water is prevented from evaporating and exiting through the breather system.

It’s your choice there Captain Nemo.