New scooter chic attempting oil leak fix  By  melidaatx (Read 2,180 times)

Scooter motors a pretty simple (as far as motors go) so there are only a few common leaky spots. The valve cover, the head gasket, or the base gasket.



Unfortunately all three are hidden underneath the plastic cooling shroud. Once you get a leak, the air from the engine fan blows the drips around and you have oil everywhere. You'll just have to start digging to find out which is the culprit. You may also want to check that the breather tube attached to the top of the valve cover is still connected to something at both ends. Otherwise it will be venting oil mist in to your engine compartment,

My Znen seems to have a similar leak. I simple green cleaned the engine bay and hosed it out with water. Also added a new breather line and went to a clean fuel filter mounted up high towards the back. Didn't help. (I think I forgot to plug the port on the intake plenum)
The oil is seeping on to the floorboard, and out through the gills slits below the seat. My valve cover is tight, but it is time to check the gasket, and head torque, and valve clearance.

Interestingly, this leak issue did not start until the last oil change - Rotella 5W-40 synthetic. I will either try 15W-40 synthetic or dino oil 10W-40. But since it is already leaking, I doubt a simple change will help.

I just watched this video on how to adjust a valve cover... I think I may be in over my head :-(

Its not adjusting a valve cover,,its adjusting the actual valves on that video,,the cover is just a cover held on with a few bolts and a sealing O-ring to keep the oil in.Also on that video,,after he took the cover off,,did you see those four nuts?Well those are the head nuts I was talking about that need to be snugged up or torqued to 20 foot pounds.

Mine had a drip up there,,what I did was take the valve cover off to adjust my valves,,then torqued or tightened the head bolts up to 20 ft pounds(or right when they are about to twist),,then I applied Indian Head Shellac to the valve cover where the O-ring seals and put it all back together,,no more leak.

So if I where you I would try to see if the leak is coming from around the valve cover or the head,,if its either I would take off the valve cover and put a new O-ring there,,while its off just snug up the head bolts,,you may need to take off most of the plastic covers to get this job done.Too bad your not closer or I would do it for you in an hour or so

Tom ;D

BTW-Changing over to synthetic oil can find a leak that was not there with dino,,the syn is so much slicker and has better flowing properties.There are other seals that can leak besides the ones mentioned,,there is one behind the variator and one on the stator side,,they are crank seals,,but Im sure yours is from the valve cover/head area...

Thanks for the encouragement! I'll try again tonight.

The black plastic cooling shroud is there to help direct the air from the fan over and around the fins on the cylinder and head. You could run the motor without the shroud but not for very long before it would start to overheat. For testing you could set up an electric fan to blow air at the motor. Unfortunately the shroud is covering over all the joints between parts that you want to get a look at. Whether or not you have room to remove it, (or the valve cover or anything else), will depend on your particular model of scooter and the bodywork around it. On my 150 the front of the motor sits quite low so I can't do much without removing the whole engine assembly from the frame. Not as bad as it sounds, but still time consuming.