Valve Seals

[ny300exrider]

i think my valve seals are beginning to wear out on my 400ex. im not very good with motors yet and was wondeirng exactly what they do and an estimate price on how much new ones are and an estimate on what a regular mechanic would charge to install them. the symptons of my quad are it smokes when started for about one minute and then stops. i think oil gets passed the seals and then eventually burns off. the one thing that concerns me is if i ride my quad full throttle for like 10 seconds it will blow out some blueish smoke. would valve seals cause this by any chance or is it defintily something else like rings. anyone who had to replace their seals, could you tell me what your quad was doing so i can figure out my problem. The quad defintly doesnt seem to be loosing power and it runs good.
thanks

[Aceman]

Yeah, sounds like you need to replace the valve seals. Service Honda says 4.82 per seal. So I would guess a dealer would charge you maybe 25-30 for all 4. Probably around an hour and a half to install. I've done the valve seals on my 300ex with the engine out of the frame so I'm not sure how long it would take with it in the frame.

[hondardr4life]

I dont wanna mess up his post, but I am rebuilding my 98 300ex with a 330 kit, and I hav emy motor all torn down. My question is, should I go ahead and replace my seals while my motor is in pieces? And how hard are they to replace?

[mojoe2878]

i have a reciept for a set of 400ex valve seals i replaced a couple months ago for someone and they were $28.44 for all 4 seals from the dealer. you have to remove the valve springs and retainers and stuff to replace them, its not hard at all if you know what you are doin or if someone can guide you thru it the first time, but the head will need to be removed to do it, unless the shop has a special valve compressor that can allow you to remove all the retainers and springs without the valve dropping into the cylinder, if you take it somewhere i think you would be looking at 3 to 4 hours of labor plus the parts, so whatever the shop charges for an hour of labor will determine the cost(usually anywhere from $45 to $65 an hour). keep in mind that a lot of dealers wont install a part that was not bought from them.

[hondardr4life]

I have my head off already and my uncle has this tool that compresses them or w/e so that they will come out. And I have to take out the springs anyways to pu tin the HD ones that come with the 330 kit.

[ny300exrider]

k guys thanks a ton. i know a local dealer thats real cool and most of them ride bikes and quads. they even have a xr50 track in the back and stuff. im going to call them up tommorow to see how much an hour they charge for labor and an estimate time they can do valve seals in. once again thanks for all the help