400EX Smoking after oil change

[rooster300ex]

My dad just bought an 02 400EX. Anyways the quad has been traded back and fourth for all kinds of different reasons to people I know. Anyways my dad just got the quad, and he wanted me to change the oil. I'm prolly the last person to change the oil in this thing, i've changed the oil in it several times, but this time after the oil change it smokes on startup a bit and clears up, and runs strong. I bet it only smokes for about 30secs. Is it the valve guides or what could cause this. Is this my fault? I have changed oil in quads for alot of people, so I know what i'm doing. Especially when it comes to a 300 or 400ex. Oh yea the oil i'm running in it is lucas motorcycle oil 20-50 since the hot months are coming.

[tri5ron]

Sounds to me, through all the other people riding it, and possibly not keeping clean oil in it,... like the valve seals are starting to go.

I'm assuming it is a Grey - Blue/Grey colored smoke ?

White smoke,
would indicate some water/condensation in the exhaust. (possibly from washing the quad ?)

Black smoke,
would indicate it is running too rich.
(is the airfilter clean ?, or has anyone messed with the carb?)

I'm also assuming it has FRESH Fuel in it, and your valves are properly adjusted.

[rooster300ex]

Originally posted by tri5ron
Sounds to me, through all the other people riding it, and possibly not keeping clean oil in it,... like the valve seals are starting to go.

I'm assuming it is a Grey - Blue/Grey colored smoke ?

White smoke,
would indicate some water/condensation in the exhaust. (possibly from washing the quad ?)

Black smoke,
would indicate it is running too rich.
(is the airfilter clean ?, or has anyone messed with the carb?)

I'm also assuming it has FRESH Fuel in it, and your valves are properly adjusted.

The oil was really black. Yes its oil burning for sure blue oil smelling smoke. Valves sound good and quiet. Yes fresh fuel 91 with alil 101 in it. I'm afraid my dad is gonna think I messed it up or something. Thats why i'm making this thread. Anyways why would changing the oil cause this? Is it because putting the new fresh oil got the gunk out of the seals and now there leaking. It takes a whole day for it to smoke on startup, But after starting it that one time it doesn't do it for the rest of the day till it like sits overnight or longer.

[tri5ron]

Classic Valve seals symptoms.
I highly doubt you did anyting to cause it.

[CJM]

Probably drained the gunk that was holding the valve seals better together. This isnt a huge deal, valve seals wear out, change them when you take off the head or leave it be and keep up on checking the oil.

[rooster300ex]

Are valve seals called valve guides also? I'm lookin at an oem parts finder and I just see valve guides and o-rings. Are the seals the o-rings? I know alot about quads except for internal engine things.

[hocman123]

no valve guides a things that get pressed into the head. u need valve seals http://www.rockymountainatvmc.com/oem/id/1.2 it is # 1

also i would suggest buying this tool i have done it with out this tool a few times and it was a pain but after i got it replaceing seals were easy http://www.rockymountainatvmc.com/productDetail.do?navType=type&webTypeId=140&navTitle=Tools%2FShop&webCatId=22&keyword=valve+tools&prodFamilyId=16404

[rooster300ex]

Alright I got it now. Wonder how much a shop would charge to do this?

[hocman123]

i am not sure i do all my work myself but i know most shops charge around 75-95 dollers a hour for just labor sometimes more. amd i would think it would take a good shop anyware from 1.5 to 2.5 hours to do the job depending if they re ground the valves for u when they have it apart

[rooster300ex]

I'll give a honda shop a call and see how much it is, cuz me nor my dad wanna tear into any part of the engine. As fas as I go is takin the oil filter cap off. lol
How far do they have to dig into the topend to get to the valve seals?

[kaleb]

if they did not change the oil filter it will do that

[hocman123]

Originally posted by kaleb
if they did not change the oil filter it will do that

well idk what u mean by that if u don't change the filter when changeing the oil it somkes when u start it ???? that makes no sense to me one has nothing to do with the other.

rooster in order to do the valves seals u need to first take off all the plastics the gas tank the carb and the heat shield. then u need to remove the upper engine mount the goes across the top of the engine. all of that just to get to the engine. then u would need to take off the valve cover remove the cam and remove the head off the top of the cylinder. the valves are in the head. u would not need to remove the cylinder or have to do anything to the piston.

[rooster300ex]

Originally posted by kaleb
if they did not change the oil filter it will do that

Yea i'm not understanding what u are gettin at. Are u sayin if they didn't change the oil filter that would allow junk to get into the valve seals and seal them up, and then when I changed the oil and filter it cleared it all out??

[CJM]

To add to it all, you will need to either purchase a valve spring compressor from rocky mtn or figure out a way to do it yourself.

Might be worth the labor to take the head off yourself then have the honda shop just do the seals. Curse depends on just how mechanically inclined you are-if working on the engine intimidates you dont do it.

As for not changing the oil filter building up sludge-no not changing the oil or not doing it often will do that-not just the filter. This is because the oil breaks down and becomes sludge and gets trapped cause its gunk by this point.

[rooster300ex]

Ok update I tried something. If I start the quad and hold the throttle about an 1/8-1/4 until it will idle on its own it doesn't smoke at all on start up. But when I start it the first time for the day and give it about 1/2 throttle and hold it it barrels out the smoke for 30secs. It doesn't smoke unless I do that???????????. Still worn valve seals???

[CJM]

Could just be too rich jetting and thats gas your throwing out the tailpipe.

Does the exhaust smell like gas?

[rooster300ex]

Originally posted by CJM
Could just be too rich jetting and thats gas your throwing out the tailpipe.

Does the exhaust smell like gas?

Naw its oil. This bike has never done this before nothing has been changed on this quad since me and my friend went and bought it, and then it got traded around but not really rode much at all.

[CJM]

Id venture to guess that the reason it doesnt smoke when you start it holding the throttle is the fact the oil is circulating more b/c your putting a load on the engine.

Unless your losing tons of oil then Id not worry about it. If anything when you changed the oil the new oil probably cleaned out all the gunk built up in there from lack of changes. Could be so bad that the gunk might still be in there-the valves might be covered in it.

[rooster300ex]

Originally posted by CJM
Id venture to guess that the reason it doesnt smoke when you start it holding the throttle is the fact the oil is circulating more b/c your putting a load on the engine.

Unless your losing tons of oil then Id not worry about it. If anything when you changed the oil the new oil probably cleaned out all the gunk built up in there from lack of changes. Could be so bad that the gunk might still be in there-the valves might be covered in it.

I checked the oil and its still on the full mark. But it hasn't been for a days ride yet though. Then I'll see if its burning it up.

[rooster300ex]

Its getting better about not smoking on startup the more my dad rides it?????

[CJM]

IDK man, wish I did.