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Can engine crack in water crossings?

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On my trails often go through shallow creeks. Has anyone ever heard of damage to the engine/exhaust due to parts being a couple of hundred degress and getting dunked suddenly in cold water? i never really thought about it until my friend said something. in theory he is right so know i am afraid to cross the water again until i get some reassurance. thanks guys

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along time ago i was cleaning my good ol' pw80 after it was soaked in mud. The engine was still hot and i sprayed the engine down with a hose and the cylinder suddenly emitted a bunch of steam. My father stated "dont do that, you could crack the block"(cylinder, yea hes a car guy) It makes sense but I've yet to see it happen. I dont do it just for insurance. Have you ever had a cup of iced tea or coca-cola and dropped an ice cube in it and hear them crack? same principle..

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the only thing that i really wonder is if the metal has been treated in a way to compensate for sudden changes in temperature. i figure the manufacturer sells them as trail bikes so they should have addressed this issue in the past. i see pics of guys doing deep water crossings all the time and never hear any horror stories. at the areas i cross i see quad tracks around the creek that have to drown most of the quad if not the whole thing. this boggles my mind they, must have a snorkel on the airbox or else it would be impossible.

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I think this falls into the theoretically possible, but never gonna happen category. If it is realistically possible, you would see lots of stories on the 'net about it. If you look at materials that commonly fracture from sudden temp change, they are brittle like ice or glass. Aluminum is pretty maleable (sp?). For an even better example of what can happen than the ice cube in a drink, try shooting a nice and hot light bulb with a squirt gun! Fortunatley, I didn't get cut, dad wasn't home, and mom went easy with the yardstick for being stupid :cry:

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As long as the engine is running it shouldnt do any damage. It is when the engine isnt running when all of the damage happens. Think about it, why would they put a "snorkle" in the air box if they didnt plan on water getting that high? I only wash my bike after it has cooled down. My experience...had an exhaust manifold (1984 Blazer) crack on me when I was washing the engine off. That was a stupid mistake.

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I have seen bikes and quads drowned in rivers and ponds and haven't heard of one cracked motor yet, with the motor off I suppose it could cause some warpage possibly. I always let mine cool a bit before I wash it off just to be safe, but riding I never pay any attention to water less than seat high. :cry:

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what about that guy that goes "skiing" on the water with his like wr400 or 450? h said hes drown it and nothing ever happened. i dont do it either for safety reasons, as it probably wouldnt be good to constantly spray the cylinder, but it wont kill it if you give it a little squirt for fun. i dont know his name but if anyone does, ask him, he said hes drown his bike once in a lake

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what about that guy that goes "skiing" on the water with his like wr400 or 450? h said hes drown it and nothing ever happened. i dont do it either for safety reasons, as it probably wouldnt be good to constantly spray the cylinder, but it wont kill it if you give it a little squirt for fun. i dont know his name but if anyone does, ask him, he said hes drown his bike once in a lake

i saw that pic on this forum, i know excactly who you are talking about. i would love to have areas to ride in like him, i believe he's located out west.

since we are on the subject, just how deep can i sink my bike before i drown it? keep in mind i have made no mods to prevent drowning like snorkels, packed plugs ect. i always figured like the guy above and never took it to where i may flood the airbox or exhaust outlet hence anything below the seat was cool with me.

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I never actually sunk the bike in the lake but I have dropped it completely underwater a few times during slippery stream crossings. I did sink my sled crossing the lake. The engine was hot when it went under, the water was about 2 or 3 degrees above freezing, no problem, and I had the engine running a few minutes later.

When I run the bike across the lake the engine is constantly blasted with near freezing water. I was making passes one after another for over an hour with no problem. The engine is getting blasted with water each pass for 20 -30 seconds.

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I'm no expert on metallurgy but here's some things to think about. If you heat or cool something uniformly it usually doesn't distort or crack. If you cool one spot of something hot it may cause a crack. Cooling the spot shrinks the metal. The surrounding area is still hot. Maybe this causes the crack. When you weld cast iron you have to heat the area uniformly before you weld and wrap the piece with insulation to let it cool slowly and uniformly.

I've heard that if the barrel of a rifle gets hot from constant firing, you can cool it by plunging the entire barrel into water without warping it. If you dip it slowly it'll warp.

The bottom line is if I'm not cracking anything with near freezing water temperature on a hot engine, it's probably a rare thing.

Of course I may be wrong. I'm just making this up as I go along. :cry:

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With todays parts being steel and aluminum the risk is not nearly as likely as it used to be when iron was used more commonly. That's why the exhause manafold above cracked, it was probably cast iron. Both steel and aluminum are more malable so they can take the stresses. I'm not saying go dunk your bike in freezing water to see if you can crack something. Crossing rivers (lakes :cry:) should not be a problem at all.

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Yes, when you jump into the stream and case it hard on a rock that you did not see.

Don't do that. It's a long wet walk home, trust me.

Cheers,

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or if you go under with the throttle pinned and suck in a lung full of water that hydraulic locks the cylinder, the connecting rod may poke a little hole in the engine. :cry:

If you're going under and the engine is still spinning, grab the decomp lever and hold it in to relieve the hydraulic pressure until the engine has completely stopped. If you have the presence of mind (and love your bike enough and can hold your breath long enough) to actually pull this off while you're sinking, brother, you've got skills! :cry:

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The only person I've ever known to have had a problem with this is my dad.

He bought of the very first Sportsters (1955ish I guess). He had gotten it REALLY hot riding around in traffic, so he stopped at a gas station and sprayed cold water on the rear cylinder. A very loud cracking sound convinced him that his idea was a bad one. The continuous stream of smoke from the exhaust from that day forward confirmed that his idea was infact a bad one.

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thanks for the replies everyone. i am confident once again. as soon as i mount my new tires and rebuild my front brakes i will be back in the water.

and on a side note...frostbite you are nuts :cry: you look like you take it with some speed, i am so scared of wrecking and laying the bike over. are you saying you had the bike running a few minutes after dropping it because i was under the impression i should prepare for the long, wet hike if that ever happened. any tips on restarting after a drown?

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In the post I said I had the sled running a few minutes afterwards but it didn't take much longer to get the bike going. The bike was only under long enough for me to get back on my feet and stand it up so the water didn't have much time to fill things up. If it's a quick dunk you may be able to restart mid stream but most of the time I had to push to shore, pop off the gas line and crack the petcock a bit to see if a bit of water got in the tank, drain the carb if you have tools, if not, turn the gas off and turn the bike as upside down as possible to get any water out via the vent tubes, take out the air filter if you have tools, if not, try to pop the filter boot off of the carbto let dry fresh air in, remove the spark plug if you have tools and kick over to blow water out of the cylinder, if not, hold in the decomp and kick over as fast as you can with the throttle WFO. Wring out your gloves and use them to dry the coil and wires off as best you can.

Like I said, the bike was only under for a short time, definitely less than a minute, and I've always been able to restart.

My sled was under for a while and the cylinders were completely full, but I took out the plugs and pulled the engine over until it was gone. First it was squirting pure water, then mist, then fog. I drained the carbs, no water got in the tank, wiped off the coils and wires and it fired up. It was a bit groggy at first but cleared up quickly.

The only real adverse effect I can see that cold water has is your buddies aren't quite as quick to jump in and help you out. One of my riding buds found this out the hard way :cry:

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I guess this proves our cast iron theory.

The first sportster was produced in 1957, and the cylinders were cast iron. :cry: My dad actually has a running and restored '57 sportster in the garage.

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This is a really good post!, last week i had my bike up to the seat in ice cold water, part of the trail, the thing kept wanting to tip sideways and float out from under me and died once, me being up to my nards in the icey stuff and not wanting to push the bike out i tried to get it started agian, bad idea, it sucked a bunch of water in through the bowl on the bottom of the carb, after i pushed it out and drained the card and it dried out it ran fine, hopefully i didn't do any permanent damage, Brad.

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I ride alot of deep water crossings and have for the last 38 years, during that time I've drowned my share of bikes 2 ans 4 stroke and only once have I done serious engine damage, after failing to jump a small pond on a 84 CR500 and landing in 5' of cold water!!, this resulted in a cracked piston skirt!. Other than that nothing. So I would'nt worry to much other than the pain in the but to flush out a drowned bike and replace fluids it's no big deal,(we're talkink about submarining a bike). Even deap cold stream crossings are no problem as long as you don't suck water thru the intake tract!!. Never the less make sure the bike is prepped correctly, dielectric grease on all electrical connections,re route carb vent hoses,no open crankase vents below the airbox, no vacum leaks,ect. :cry:

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As long as the engine is running it shouldnt do any damage. It is when the engine isnt running when all of the damage happens. Think about it, why would they put a "snorkle" in the air box if they didnt plan on water getting that high? I only wash my bike after it has cooled down. My experience...had an exhaust manifold (1984 Blazer) crack on me when I was washing the engine off. That was a stupid mistake.

I was told many years ago by a surrogate dad that I adopted when I was a kid (he was a neighbor that raced bombers on the local oval track), that an engine will be at its hottest just after shut down. Due to the lack of coolant flow.

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