burned values??

[Hanchett]

Hey WR riders, a friend of mine burnt up his values in his WR because he said he went through water and it splashed on the engine. He said he heard that the WR's and water don't get along. The sudden change of tempature sill burn up the values. Ever since then I've been putting through any water/mud obstacles. Does anyone have any info on the matter? Thanks for any info!!

WR426f - son's

WR400f - dad's

KLX300 - wife's

XR50 - daughter's

[BrandonW]

Is your buddy's bike running weird after the water crossing?

I know that WR's have a little carburator problem with water crossings (venting issue that can be solved by re-routing two of the four vent tubes into the airbox) but not sure about the water temp. against the engine issue.

I submarined my WR earlier in the year. The bike and I both went under. I pushed it to the other bank, pulled the plug on the bottom of my airbox and let that drain; then I pulled off my seat and airfilter and sqeezed all the water out of that; then I turned the bike upside down and put the bike in gear and depressed the decomp lever, then grabbed the wheel and started spinning it. That pushed all the water that was in the combustion chamber out the exhaust port and into the exhaust pipe. Turned the bike right-side up, then I pulled out the drain plug on the bottom of the carb. Then, I pulled the hot start button, and started kicking. Took about 2-3 minutes of that, and she fired!

Put the air filter back on, seat back on, and finished the race! 19th in class, out of 80.

Wonder how I would have finished had I not given them 20 minutes? ?

Had to change the oil about 3 times before traces of water were gone, but I think that was it.

Unless you get "hydro-lock" damage, I think water is pretty harmless.

(Please read "Disclaimer" if I am wrong! )

PS! I DO know that if your bike dies while in water, DO NOT KICK START IT THERE! Push it out of the water prior to kick starting. The crank-case breather tube is very low, and will suck in water if it is submerged while you are kicking. When the bike is running, it won't suck water in.

[BlueThunder]

Values are a moral issue or 70% discount at the local dealership and neither should be affected by a little water ? Kidding aside, his valves burned? Lack of lubrication or severe detonation are the only things I know that might cause this problem. What part of the valve burned? Did he recently do the YZ timing mod or drastically lean the jetting? Was the valve lash within spec.? Was the oil at capacity and fairly fresh? Need more info to determine the cause but just guessing.....sucked water into airbox or vent, degraded oil, top end meltdown occurs. Just a guess though.

[freestyle111]

the oil breather hose[on valve cover] on wr and yz thumpers works like a syphon whenever end of hose is submerge in water and bike is stalled.if you stall bike in water crossing and end of hose is submerged do not try and start bike.this warning comes from experience i've filled motor with water a couple times.since water doesnt compress and vaporize like gas you can very easily damage valves if you start bike with water in cylinder.usually water in cylinder will cause motor to hydrolock and you wont even be able to kick motor thru stroke.this happens because water enters cylinder and the water wont compress enough to allow piston to reach TDC the at which point exhaust valves are open.since motor cant reach that point there is no way for water to escape cylinder.the force created by piston trying to compress water can cause valves to be broke or bent.best way to fix hydrolocked motor is pull sparkplug and turn bike upside so water can drain out of cylinder.

[yamahasocal450]

i stalled in the water once with the crankcase hose underwater so i kicked it about 5-10 times then pulled it out of the water and kicked it then it fired up... do you think ill need to take the topend apart to see if theres any more water or rust in there (it has been 3 months since then) ? thanks in advacne :D

[dominator426]

Water can't enter combustion chamber via the crankcase vent hose...only through intake (airbox and carburetor) and in extreme cases, in the exhaust. There is a possibility of water entering the crankcase vent hose onto the cams and in the oil in which case you should change the oil.

[Wayward Son]

burned values??

im fairly expensive! ?

[freestyle111]

Post deleted by freestyle111

[dominator426]

Yes, I agree. Water (and mud) is definitely undesirable on the valve train and in the lubrication system and it does cause sludge formation...What is the best way to reroute this crankcase vent? ?

[freestyle111]

dominator426, i wish i knew the best way to solve breather hose issue.i shortened my hose and added a small k&n filter.there is one big drawback with this remedy.after riding for 4 or 5 hours the oil that comes out breather hose will start to seep out filter and gets blown all over front of motor.doesnt really hurt anything its just a little messy.

[huskyrider]

What is the best way to reroute this crankcase vent?

Put a plastic tee in the vent tube and run another tube to the airbox. Natural drainage will go down the tube, and if your stalled in the drink you can kick start it without fear of water traveling backwards up the tube into the engine.

[freestyle111]

huskyrider, thanks.adding a T to breather hose would definitly fix problem with sucking up water thru breather hose.i just have 1 question.if bike is dumped in water crossing wouldn't hose going from T to airbox act as a vent for submerged end of breather hose allowing water to rush thru hose and into valve cover twice as fast? this would only be a problem if bike is laying on its side and end of breather hose is submerge in water.

[dominator426]

Yeah, even when upright, if for some reason there should be suction in the crankcase, perhaps as it cools off, pulling water up the vent, the tee would not prevent it as water could travel up both hoses. The tee wouldn't change the crankcase vent circuit and it's behavior.

Shortening it or routing it to a high position without going upwards or level at any point seems to be the best but somewhat messy way. I like the filter idea...

[dominator426]

Actually, how about installing an inline downdraft PCV valve about halfway down the crankcase vent hose? It would allow normal venting of the crankcase and would be sealed off when engine is stopped or under negative pressure. This could also be done with shorter hose and/or with filter.

[freestyle111]

Post deleted by freestyle111

[BlueThunder]

You ever get hassled by the USFS for water crossings? Up here, unless it is on a trail crossing(most have little bridges over them now) it is a HUGE fine if you get caught by the guy in the pale green truck. They say it destroys spawning beds for the fish and can actually impound your bike for the offense. What can you do, sometimes it's just unavoidable in the wilderness areas during the snow melt? But we all look around suspiciously, waiting for them to pounce on us ?

[freestyle111]

bluethunder, you mentioned a good point.i picked the area where i cross river because its private property on both sides of river.i ran in into cattle rancher that owned the property a few years ago and after a couple hours of conversation while giving him a hand clearing a fallen tree from road directly in front of his property he told me i could ride across his property and he even gave me combination to locked gate between his property and usfs ohv.im not sure but i could probably still get fined for crossing river with motorized vehicle.even while on private property but there is no way USFS rangers would catch me since they dont patrol the private property.

[Rip Wheeler]

Hey WR riders, a friend of mine burnt up his values in his WR because he said he went through water and it splashed on the engine. He said he heard that the WR's and water don't get along. The sudden change of tempature sill burn up the values. Ever since then I've been putting through any water/mud obstacles. Does anyone have any info on the matter? Thanks for any info!!

Well, water ingested into a running engine creates whats known in the industry as a "hydro-lock" and as everyone in here knows, liquids dont compress, so usually a rod gets shorter or pokes out the side. Usually burnt valves are caused by too little margin, if the margin gets thin, kinda like a knife edge, it will just burn away. A valve with good margin can also burn if the valve isnt fully seating from too little clearance. Each time the valve seats, even if tis just for a milli second, this small amount of time does allow heat to escape into the head. An engine that burns lots of oil can also lead to burnt valves, the excess oil tends to insulate it also. Now if your buddy maybe tweaked a valve (warped) from being real hot, then cool, but usually the valve goes back to its original shape and this is rare to actualy burn a valve this way. Is his compression low? ?

[dirtstiff]

I appreciate that humor Eddie. Going Mullet Blue after all or just taking a break from the " current wisdom " being shown on the Yellow side? Anyway, your welcome in this crowd. ?