Swamped Engine

Last night my friend with a new WR426 was trail riding and went to cross a mud hole. The hole was deaper than he thought and ended up with the motor submerged, but not the carb or the air box. The motor stalled on him when it was under water. When he got it out it took like half an hour to start it, then a bunch of the oil came out the vent tube. I told him that he better not run it more than necesary to get back to the trucks. When he drained the oil we found that there was water in the oil, and when the filter was removed it was full of sandy mud.

I am just wondering if anyone has run into this problem? I was also wondering if a person could reroute they vent tube to go along the frame closer to the airbox hieght and maybe vent by the rear tire, instead of down the front of the motor?

I don't have personal experience with this bike in water, but I have read on here that it can suck up water if you try to start it with the vent tube under water. If he's got mud in it then I would personally take the motor apart and clean it out before running it any more. I imagine that it will be quite a while before the filter catches all of the mud and you don't want that in the gear box and motor at all.

Hey Talon!

So Sorry to hear about your WR woes!

I too did the same thing. I buried my YZ in a bad mud hole-stuck it good! I tried kicking it over repetitively to get it going again. She wouldn't start.

The vent hose was below the mud line and each kick that power plant was sucking mud and water into the case. When I finally was able to get the bike out of the mud, and home, I drained the oil pan. I got about 2 gallons of water out before oil started to flow. It took me about 5 flushes with oil and one with motor flush before the oil was coming out clean.

Thank the LORD, I suffered no damage. This became evident when I opened the bike up to do the clutch basket. Not a wisp of mud, slit or any damage!

Take your time, and flush the bike out.

I will say this: I don't know if the motor flush treatment was exactly the right thing to do to this kind of motor. I didn't do it repetitively, and under no circumstances did I rev the engine with that stuff in it. I just let it idle without the choke on.

I'm sure that some will say that's okay, and others here will say not a good move. Find out. I talked with mechanics before I did this.

Also-Yank the frame filter. It WILL be clogged with silt, mud and any debris you picked up. I used the same replacement filter cleaning each time with brake fluid.

Take Care!

And Best Wishes!

God Bless!


YZ426 Kicks

I swamped mine but good.. :)

Had to drain the carb with the allen screw.. the filter was right slugged up with contaminated oil.. (I imagine that's whats in yours) Can't see mud getting to the filter .. but who knows..

I changed the oil about 5 times with just cheap regular car 10w30 until it came clean .. after 2 time I ran it for about 30 seconds to cycle it through.. then drained it again..

Make sure u clean that filter each time, the sludge will choke the filter off.

It'll be fine i'm sure

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now