I had a little run in last week with my 400EX and a 7 ft deep beaver swamp out back of the house.Needless to say the ice did not hold up as I thought it might.Anyways I finally got it out which is a whole story on its own but later when I tryed to start it,it just turned over and sounded like it was knocking pretty bad.I know it got water in the engine even though it was kinda floating.I have the engine torn down now to the point of the cylinder being off but the case is still on the quad.Piston and rings looked good but should I get new rings?It seemed to seal pretty tight.I am planning on just putting this back together on a minimal budget.So far all I know I need is gaskets.Could it be possible the crank bearings are bad?How can I tell?I would hate to put it back together to find out it needs to come apart again.What could have caused the knock?Could the valves be bad?How do I put this back in time once it is going back together(with the chain and cam)?Would it be worth it to go with my first plan and throw in a standard bore 11:1 compression wiseco piston and maybe a stage 1 hot cam?Also am I going to have to do that stud fix because sometimes the head gasket or cylinder gasket or something starts blowing?

I am sure I am forgetting something.Please someone help.I really want to do some of this powder snow riding with it.

Thanks,
Ron

 

No one?Someone here has got to be able to help me.I think...lol

 

replace the rings and make sure All water is out and GRAY looking oil it will eat the crap out of it then put it back togeather then run at least 4 to quarts of new oil drain every time . then it sould be good

 

I assume you just fell through the ice all of the sudden and took water into the engine while it was running. Is this correct?


Before you tried turning it over, did you take the spark plug out, drain the oil, etc.? If not and you had water in your cylinder, you could have a multitude of problems.

Give some more info and you will get more help.

/Jon

 

Yeah it got water in through the exhaust and it looked like there was some in the cylinder.I did try to turn it over a couple times before taking out the plugs.Was that a no no?

 

Yep, big "no no". The damage would most likely occur after the intake stroke when water is sucked into the cylinder then on the compression stroke all the valves are closed so the water has no way to escape. Since water doesn't compress much if at all, something must give. I would think the piston or piston rod would be the first to go but I guess it would be possible to twist the crank too.

On the exhaust stroke, I am not sure the valve would open enough to let the water flow out quick enough so it is possible you bent a valve. Any shop can quickly check the head for you. Taking the plug out creates a bigger hole to allow the water to escape freely on the exhaust stroke.

Believe me, you aren't the first nor will you be the last to try to start an engine after submerging it. Chances are though, the damage was already done. If it was the actual intake of water that killed the engine, it was toast before you even pulled it out of the water.


/Jon

 

id say its time for a 460 stroker. chances are u bent the rod maybe some valves, cams arent that expensive, and ur gonna have to split the case...so why the hell not. sure it isnt cheap but u might as well since ur gonna have to do all the same work to put it back to stock, then u will have one badass machine my friend.

 

I dont know now.After rethinking I dont know if it sucked the water.I forgot to mension it was tipped up while it was running but then I shut it off and after it went in the water which could explain how water could get in without ruining it.I think I am going to try the rings and gaskets first but ill report back later and let you know.

Ron