YZ went swimming

Brother in law fell off the bank on a little stream. Bike ended up upside down resting on it's handle bars in about 1 foot of water. The bike had already stalled by the time it hit the water. We picked it up and tried to start it. All of a sudden he didn't need to use his autodecompression lever to kick it anymore. (It's a '98 yz400). So we stood the bike up on it's back wheel and sure enough water poured out of the tail pipe... We slowly cranked the kick while it was standing on the back tire and for the first two cranks a little more water came out of the pipe, but no more after that... It still had some decent compression, but not the normal amount for a 400. While I went to get the truck he tried bump starting it once, and it almost started, or it tried to at least. Then when he was kickin it again later it kinda tried to start again. So... what's the good news / bad news?

Drain the Oil.. replace the plug, after spraying some WD-40 in the hole.. Give it a shot.

Here's an update for anyone who may stumble across this in the future. Brother in law took the cylinder head off his bike, there was all kinds of mud, water and crap in there. Piston rings were stuck to the piston. He ordered new rings and gaskets. His dad is going to hone the cylinder, clean up the valves, and clean out the carb. I'm trying to talk him into re-shimming his valves if they need it.

throw a new timing chain on the order while you are that close....

and a ad exhaust cam too!!!

throw a new timing chain on the order while you are that close....

and a ad exhaust cam too!!!

Your preaching to the choir dude. I'm working on talking him into those two pieces. It's a $$$ thing though.

It was a pain in the butt to install but in the end was worth it, when I did those two to my bike.

get the chain at the least... there was a thread on here not too long ago with a chain only like 9 mo's old and was stretched. the lower gear is part of the crank......

see ya

Yeah that's pretty gnarly. Thanks for the link. Was reading that thread, and noticed the link someone put up for a price on the timing chain. It's $11.36 cheaper than bikebandit.com.

Here's the link

http://www.boats.net/parts/search.html?Manufacturer=Yamaha&Catalog=Motorcycle&Year=1998&Model=23921&ModelName=YZ400FK+MOTOCROSS+4-STROKE&Component=114426%7C%7C620200990004%7C%7CCAMSHAFT+CHAIN

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