Rebuild Question - Valve Seals??? | cvetitula.ru
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post #1 of 13 (permalink) Old 04-05-2012, 12:30 PM Thread Starter
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Rebuild Question - Valve Seals???

My 400ex started burining oil and actually burned all the oil out without me realizing it. I filled it back up and it started smoking like a chimney. But when it gets warmed up it doesn't really smoke at idle nut when you give it throttle it shoots out what looks to be light blue smoke. (The bike was always ticking but since I changed the oil the tick has gotten incresingly louder) I know I need to adjust the valves.

A friend of mine said it could be the rings or the valve seals. My question is once I begin to break it down how do I know if the valve seals are bad?? Can anyone give me some ideas how to daignose bad valve seals?? Once I get to the piston I am familar with inspecting and replacing the piston but I am completely new to inspecting and troubleshooting valves.

Also would valves that need to be adjusted cause the bike to smoke??

Thanks

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post #2 of 13 (permalink) Old 04-05-2012, 02:14 PM
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Valves are pretty simple. . once you have the head removed you can then remove the valve springs. Once the springs are removed the easies way I can tell you to check the seals is to push the valve all the way up into the seated position and let go of it. If it falls the seals have a little wear, the seals should hold the valves in place, also if you push and pull on the valve it should have some resistance. If ithe engine has never been touched then i would say it's time for some seals. While you have the valves out get some fine valve grind compound and re-lap the valves so the will seat properly. Make sure you put the valve back in the port it came from too. Also when you reinstall the springs make sure you install the springs with the tightly wound coils towards the piston

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post #3 of 13 (permalink) Old 04-05-2012, 02:58 PM Thread Starter
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That sounds pretty simple, do the springs jsut come off by hand. I have heard some people mention a certain tool you need to use but like i said I am pretty green when it comes to valves.

Can you just pull the springs off or is there a certain way they come off?

Thanks for the response.

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post #4 of 13 (permalink) Old 04-05-2012, 07:26 PM
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you will need a valve spring compressor to press the valve down to remove the Valve keepers

"MOOSE WAGON "
00 TRX400EX aka "MOOSE ROCKET"
91 TRX250X aka "MOOSE WAGON" RETIRED
96 Polaris 400L sport (Mrs. Moose Ride)
07 Suzuki LTZ250 (Sons)
96 Polaris 250 Trail Blazer (daughters)
06 TRX450ER aka === Under construction

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post #5 of 13 (permalink) Old 04-05-2012, 10:49 PM
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I wouldn't even bother trying to check the valve stem seals. They're inexpensive and easy to replace since you will have the head off anyway. I would just go ahead and change them, so you don't end up having to go back into the engine again.

Most 4-wheeler problems are caused by a loose nut connecting the handlebars and the seat!!

You only need two tools in life -- WD-40 and duct tape. If it doesn't move and should, use the WD-40. If it shouldn't move and does, use the duct tape.
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post #6 of 13 (permalink) Old 04-06-2012, 08:32 AM Thread Starter
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OK, I was just looking at prices and they pretty inexpensive. Is it as easy as just removing the old seal and putting the new one. The manual doesn't give any real specific instructions on how to put each valve back together once you have it removed.

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post #7 of 13 (permalink) Old 04-07-2012, 12:22 AM
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Yep, once you compress the springs and remove the keepers and disassemble the valves, just pull the old ones off and put the new ones on. Lube the inside of the seals and the valve stems before putting the valves back in. Also, as you're putting the valves back in, twist them as you're pushing them in so they slide in easier without damaging the seals. And when putting them back together, make sure you don't put the springs in upside down. The end with the tightly wound coils goes down.

Most 4-wheeler problems are caused by a loose nut connecting the handlebars and the seat!!

You only need two tools in life -- WD-40 and duct tape. If it doesn't move and should, use the WD-40. If it shouldn't move and does, use the duct tape.
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post #8 of 13 (permalink) Old 04-07-2012, 09:27 AM
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Quote:
Originally Posted by Helmut View Post
I wouldn't even bother trying to check the valve stem seals. They're inexpensive and easy to replace since you will have the head off anyway. I would just go ahead and change them, so you don't end up having to go back into the engine again.
I agree dont bother checking, just get new ones. Some top end gasket kits comes with valve seals, so check that before you go off and buy some. Namura sells a top end gasket kit that runs about 40-50 bucks that has seals in it. In all honesty, if you dont know anything about head work, just pay the few bucks and take it to a machine shop with your new valves. sometimes it is better to pay someone who knows what they are doing, and get it done ONE time rather than doing it yourself twice.

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post #9 of 13 (permalink) Old 04-07-2012, 09:32 AM
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oh, and Helmut, ever tried Kroil? its waaaaaay better than WD-40 when using as a lube, it just has a really strong odor. It will with stand the elements of weather much better and longer. I have always used WD-40 when dealing with electrical issues and moisture.....thats what it was made for. You probably know this, cause you seem pretty mechanical.

WD-40= WATER DISPLACEMENT-formula #40.

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wiesco 11.1:1 440kit
a few little secrets
and soon to come...
transmission WITH REVERSE
RIDE YELLA!!
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post #10 of 13 (permalink) Old 04-07-2012, 12:31 PM
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Originally Posted by toXic View Post
oh, and Helmut, ever tried Kroil? its waaaaaay better than WD-40 when using as a lube, it just has a really strong odor. It will with stand the elements of weather much better and longer. I have always used WD-40 when dealing with electrical issues and moisture.....thats what it was made for. You probably know this, cause you seem pretty mechanical.

WD-40= WATER DISPLACEMENT-formula #40.
i use wd-40 like it's going out of style..i'm a firm believer in it !. best stuff they ever made..oh..in case you did not know ?..wd-40 helps with sore joints in your hands and fingers !!!..don't beleive me ?..try it next time your fingers or joints are sore !!!.

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