Smoking----Too much oil?

[Flatwoods Flash]

I recently bought a used 2002 400ex. The guy I bought it from was running it with way too much oil in it. I have rode it some but haven't been able to change the oil in it. Yesterday I noticed that when you rev it kinda high and let it start to die back down it will let out some bluish white smoke. It smells like burning oil so I immediately thought piston rings or valve seals or something along those lines. Then I thought to check the oil, thinking that if it was burning oil that it would be needing oil. So I checked it and it was way to high. So my question is, would running too much oil cause the motor to smoke during high rpms?:confused:

too much oil makes the oil turn bubbly & not nough get to the engine or something so it burns up piston rings if im right from what someone else told me...i might be wrong though

[LazeR]

to much oil causes blow by, it basically pushes through the rings and gets inside the combustion champer which will cause it to smoke! Its really really hard on the rings, i would change the oil or at least let some out

[throwinitup]

well yeah it can make the oil foamy b/c it can come in contact with the crank, creating a big blender i guess is a good way to look at it and yes it causes blowby...

[Flatwoods Flash]

Yeah well I changed the oil and put the right amount in it and it still smokes. It only smokes when you rev the crap out of it, or when you take off wide open and take it into the upper rpms. SO what do yall think it is? Piston rings or valve seals or what?

[ny300exrider]

my quad does the same exact thing. it will smoke but only if its completly punched hard or ridden in a high rpm for awhile. i think its valve seals because im pretty sure if it needed rings it would be smoking consistantly. Im pretty sure a quad needed a rebuild will be smoking when its being regularly riddin?? anyone want to share their opinion?? i want to know before i start pricing stuff out

[ny300exrider]

bump...anybody care to share their opinion on what the problem with our motor is. does it sound like valve seals?

[ny300exrider]

bump...

[Dalex]

If it were just the valve stem seals more than likely it would just smoke after sitting awhile,until it gets warmed up, and burns off all the oil that has gotten by the valve seals, when the engine is nice and hot the valve seals will usually swell up and not let the oil by. did this quad sit without being started for a long time?

One of the rings may be stuck. My 400ex does the same thing you explained yours is doing, I just ordered an 11:1 piston, stage 1 hot cam, cam chain and high Rev limiter, cost me just over 300 dollars and thats without the top end gasket.

While you are in there make sure you do replace the valve stems also I re-ringed my 300ex and didn't replace the valve seals and it boils smoke out of the exhaust after sitting a couple of days on
startup then stops once it is warmed up.

[ny300exrider]

hmm so my motor might need rings? it smokes when started after sitting in the cold for a few days and the only other time it will smoke is when riddin in high rpms or when its revved real high

[throwinitup]

i would say it needs rings....and, idk if u do or not, but dont rev it when its cold, and you shouldnt rev it to high hell when its just in nuetral or u have the clutch sitting there...bouncing off the rev limiter while your not moving is a bad thing... :eek2:

[Jpoutlaw250R]

Hey, a way to know if u need rings is to take a compression check, then add a lil bit of oil into the cylinder, then if the compression bumps up very much then ull most likely need rings. or if its stock check the book for lowest compression suggestion and see if its above that.

[BSTURDIVANT]

The 400ex engine is really hard on oil rings! The engine oil temp runs real high and also the high cylinder temperature takes the tension out of the oil rings.

The compression rings could show good, but the oil rings still let oil by!

[ny300exrider]

i havnt hit the rev limiter ever, i cringe when i hear guys reving their quads to the moon. the weirdest thing is when i was riding in the snow a few days ago i was 5th pinned for a good 15 seconds down an open road and i looked back and didnt see smoke. i might be lean but i dont know if thatd cause it. i do not feel any loss in power whatsoever. my piped 400 stayed with a piped z up until 4th gear and then he barely pulled away. i dont have a compression tester but i think i would feel at least the slightest loss in power. my big question is: could being lean be a even a POSSIBILITY to causing some smoke at high revs once and awhile

[ny300exrider]

when you say oil rings, what exactly are those. are they on the piston or somewhere else. sorry i havnt really looked into engines much

[BSTURDIVANT]

400s and most 4 stroke engines use a 3 ring design- 2 compression and 1 oil ring that is made up of a spring type of expander and a thin oil ring rail top and bottom of the expander.

When either the rings wear or a high temperature takes the tension out of the expander, the oil rails can no longer do their job of keeping oil from being pulled up by the rings and into the chamber.

[ny300exrider]

i see, thanks alot for explaining that. now if the oil rings were worn would it be a consistant smoke? im getting a puff or two every once and awhile. when regular riding there is no smoke or any symptoms of anything wrong but after some hard riding on the gas for awhile itll puff alittle out and then stop